Type Ad Tympanogram: Is There More Than Known?

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Sergul Ulus Evecan, Yagmur Kocasari, Orhan Bozkus, Yavuz Aslan, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7677560/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Objective: The aim of this study was to investigate the clinical and audiological characteristics of patients with Type Ad tympanograms and to determine whether Eustachian tube dysfunction (ETD) or other non-mechanical factors might contribute to the development of this tympanometric pattern in the absence of structural middle ear pathology. Materials and Methods: This prospective observational study included 64 patients who presented to the otolaryngology outpatient clinic of a tertiary care hospital between December 2023 and December 2024 and were found to have a Type Ad tympanogram in at least one ear. All participants underwent a comprehensive otolaryngologic evaluation, including otoscopy, nasal endoscopy, nasopharyngoscopy, and pure-tone audiometry. Tympanometric measurements were performed using standardized classification criteria. Based on clinical, audiological, and otoscopic findings, ears were categorized into three groups: ossicular disarticulation, tympanic membrane atrophy, and cases without structural abnormalities, the latter being suggestive of functional etiologies such as ETD. Results A total of 90 ears with Type Ad tympanograms were evaluated. Among these, 70 ears demonstrated no structural pathology but had clinical features suggestive of ETD, including nasal congestion, allergic symptoms, or a history of reflux and smoking. Notably, 14 of these ears transitioned to Type A tympanograms following medical treatment, and 7 ears developed Type C tympanograms during follow-up. These findings indicate a potential role of functional, reversible mechanisms such as impaired middle ear ventilation in the generation of Type Ad tympanograms. Conclusion Although Type Ad tympanograms are classically associated with ossicular chain discontinuity or tympanic membrane atrophy, this study demonstrates that ETD and other non-structural factors may also produce this tympanometric pattern. Recognizing these functional contributors is essential to avoid diagnostic errors and guide appropriate treatment. Longitudinal evaluation and medical management may aid in distinguishing transient dysfunction from irreversible structural abnormalities. Eustachian tube dysfunction middle ear effusion tympanic membrane tympanometry ossicular chain Figures Figure 1 Figure 2 Figure 3 Introduction Tympanometry is a non-invasive and objective diagnostic technique that provides essential information about middle ear function by assessing the compliance of the tympanic membrane and ossicular chain in response to changes in external ear canal pressure. It plays a pivotal role in the differential diagnosis of conductive hearing loss, middle ear pathologies, and Eustachian tube dysfunction (ETD), and is routinely used in combination with pure-tone audiometry in otologic practice ( 1 ). Among the established classification systems, the Jerger classification is most widely used. In this system, a Type Ad tympanogram is characterized by excessively high static acoustic compliance (> 1.6 mL), with normal middle ear pressure and canal volume, which typically suggests ossicular chain discontinuity or tympanic membrane atrophy, as seen in healed perforations or thin, hypermobile membranes ( 2 , 3 ). However, recent clinical observations challenge this traditional view, as Type Ad tympanograms are increasingly encountered in patients without discernible structural abnormalities on otoscopic examination or imaging studies ( 4 ). In some cases, these tympanometric findings occur in the absence of hearing loss, leading to diagnostic uncertainty and possible underestimation of clinical relevance. This raises the question: Could functional or reversible conditions mimic the Ad tympanometric pattern typically associated with mechanical pathology? Emerging evidence suggests that Eustachian tube dysfunction (ETD), nasopharyngeal congestion, reflux-related inflammation, and smoking-related mucosal changes may transiently alter middle ear pressure regulation and tympanic membrane mechanics, thereby producing Type Ad-like curves in the absence of anatomical disruption ( 5 , 6 ). Nonetheless, data supporting these alternative mechanisms are limited, and the clinical significance of Type Ad tympanograms in such populations remains underexplored. Therefore, the present study was designed to investigate clinical and audiological characteristics of patients with Type Ad tympanograms, with particular attention to functional etiologies, including ETD. We aimed to evaluate whether non-mechanical conditions may account for this tympanometric profile, and to observe whether these patterns demonstrate reversibility following medical treatment or natural resolution. Materials and Methods This prospective observational study was conducted at the otolaryngology outpatient clinic of a tertiary referral hospital between December 2023 and December 2024. The study protocol was reviewed and approved by the Institutional Review Board and Ethics Committee of Hamidiye Medical Faculty (Approval Number: HNEAH-KAEK2023/217/4350). All procedures adhered to the ethical principles outlined in the Declaration of Helsinki (1975, revised in 2008), and written informed consent was obtained from all participants or their legal guardians. Patient Selection and Inclusion Criteria Patients of both sexes who presented to the clinic during the study period and were found to have a Type Ad tympanometric curve in at least one ear were included. A total of 64 patients (40 males and 24 females) between 8 and 68 years of age (mean age: 42.59 ± 15.26 years) were enrolled. In total, 90 ears demonstrating Type Ad tympanograms were subjected to detailed clinical and audiological evaluation. Exclusion criteria included: A history of otologic surgery (except ventilation tube insertion) Presence of tympanic membrane perforation External auditory canal abnormalities Acute otitis media or otitis externa at the time of examination Clinical Assessment Each participant underwent a comprehensive otolaryngologic examination, including: Otoscopy to assess tympanic membrane integrity and appearance Nasal endoscopy and nasopharyngoscopy to evaluate signs of mucosal inflammation or anatomical variations suggestive of Eustachian tube dysfunction (ETD) Assessment of allergy symptoms, nasal obstruction, and history of gastroesophageal reflux or smoking Demographic data, medical history, and presenting complaints (such as ear fullness, autophony, aural pressure, or tinnitus) were documented using a standardized data collection form. Audiological Assessment Pure-tone audiometry was performed in a sound-treated booth by certified audiologists using calibrated IAC audiometers (Industrial Acoustic Company Inc., New York) and TDH-39P headphones. Air-conduction thresholds were obtained at 0.5, 1, 2, and 4 kHz, while bone-conduction thresholds were measured at 0.5, 1, and 2 kHz when necessary. The pure-tone average (PTA) was calculated from thresholds at 0.5, 1, and 2 kHz. Hearing thresholds between 0–25 dB HL were considered normal, including the upper limit of 25 dB. An air-bone gap ≤ 10 dB with elevated air-conduction thresholds was interpreted as sensorineural hearing loss, in accordance with established audiological criteria [7]. Tympanometric Evaluation Tympanometry was conducted using a calibrated Interacoustics AT-235 impedance audiometer (Interacoustics, Assens, Denmark), employing a 226 Hz probe tone and a pressure sweep from + 200 to − 400 daPa, performed in a positive-to-negative direction. The Jerger classification system was used to define tympanometric patterns. Type Ad tympanograms were identified based on the following criteria: Middle ear pressure between − 100 to + 50 daPa Static acoustic compliance > 1.6 mL, including exactly 1.6 mL Both ipsilateral and contralateral acoustic reflexes were tested and recorded. These tests provided supplementary information to rule out middle ear effusion and ossicular chain fixation. Treatment and Follow-Up Protocol Patients with nasal allergies, seromucous rhinorrhea, or nasopharyngeal inflammation were prescribed oral antihistamines for a minimum of 30 days, and antibiotics were added when signs of bacterial infection were present. Patients with suspected ETD received education on nasal hygiene and pressure equalization techniques. Those with confirmed ossicular discontinuity were excluded from the follow-up arm of the study, as their tympanometric findings were considered permanent. All remaining patients were invited for re-evaluation 30 days after initial diagnosis. At follow-up, patients were re-assessed with otoscopy, audiometry, and tympanometry. Additional follow-up visits were scheduled for individuals showing: Persistent otologic symptoms (e.g., aural fullness, pressure) Evolution into Type C or Type B tympanograms Clinical deterioration or need for ventilation tube placement This longitudinal approach allowed for the monitoring of tympanometric reversibility, particularly in cases where no structural abnormalities were observed at baseline. Statistical Analysis Descriptive statistical analyses were conducted to summarize the demographic, clinical, and audiological characteristics of the study population. Categorical variables were expressed as frequencies and percentages, while continuous variables were presented as means ± standard deviations (SD). The Kolmogorov–Smirnov test was employed to assess the normality of distribution for continuous data. Based on the distribution characteristics, appropriate comparative tests were selected. For paired nonparametric variables, the Wilcoxon signed-rank test was applied, whereas paired samples t-tests were used for parametric paired data. To evaluate the relationships between continuous variables, correlation analyses were performed using Pearson’s correlation coefficient for normally distributed variables and Spearman’s rank-order correlation coefficient for non-normally distributed variables. All statistical analyses were conducted using SPSS for Windows, version 15.0 (SPSS Inc., Chicago, IL, USA). A p-value < 0.05 was considered indicative of statistical significance throughout the analyses. Results At the time of initial presentation, patients reported a variety of otologic and nasal complaints. The most frequently reported symptom was ear fullness, noted in 23 patients (25.6%). This was followed by otalgia in 12 patients (13.3%), tinnitus or other ear noises in 11 patients (12.2%), nasal congestion in 11 patients (12.2%), hearing loss in 8 patients (8.9%), and a sensation of pressure in the ear in 8 patients (8.9%). In 17 ears (18.9%), the Type Ad tympanogram was incidentally detected in the contralateral ear during routine evaluation, without any associated complaint. Of the 90 ears evaluated, the distribution between right and left ears was equal—45 right ears and 45 left ears. Regarding comorbid medical conditions, 59 ears (65.6%) were from patients without any chronic illness or regular medication use, whereas 31 ears (34.4%) were associated with one or more chronic diseases. The breakdown of these conditions is as follows: Hypertension was present in 8 ears. Hypothyroidism was documented in 4 ears. Diabetes mellitus was found in 3 ears. Coronary artery disease was present in 2 ears. Laryngopharyngeal reflux and pityriasis versicolor were each noted in 2 ears. Asthma, bipolar disorder, and colon cancer were each present in 1 ear. Combined conditions included diabetes with hypertension in 5 ears, coronary artery disease with hypertension in 1 ear, and coronary artery disease with diabetes in 1 ear. With respect to smoking habits, 28 ears (31.1%) were from individuals who reported smoking more than 15 cigarettes per day. Fifty-six ears (62.2%) belonged to non-smokers, and 6 ears (6.7%) were from patients who had previously smoked but had since quit after prolonged use. Audiological assessment revealed the following distribution: Sensorineural hearing loss was identified in 10 ears. Conductive hearing loss was found in 6 ears. Mixed hearing loss was present in 4 ears. The remaining 70 ears demonstrated normal hearing thresholds. Based on combined clinical, otoscopic, and audiological findings, all ears were categorized into three groups for further analysis: Group 1 – Ossicular Chain Disarticulation (n = 4 ears): In this group, ossicular disarticulation was confirmed surgically. Two of the ears had conductive hearing loss, and the other two demonstrated mixed hearing loss, despite appearing normal on otoscopic examination. Group 2 – Tympanic Membrane Atrophy (n = 16 ears): These ears exhibited notable atrophy of the tympanic membrane. Within this group: Nine ears had normal hearing. Two ears demonstrated sensorineural hearing loss. Two ears showed mixed hearing loss. Three ears had conductive hearing loss. At the 30-day follow-up, one ear in this group developed a Type C tympanogram, while the remainder maintained similar static compliance values to baseline. During extended observation, four additional ears developed Type C curves, along with six contralateral ears that also shifted to a Type C configuration. Group 3 – No Structural Pathology / Functional Etiology (n = 70 ears): This group consisted of patients without identifiable structural abnormalities but who exhibited clinical signs consistent with Eustachian tube dysfunction (ETD). The common findings in this group included: Presence of serous or seropurulent nasal secretions. A medical history of reflux, allergic rhinitis, or smoking. Previous insertion of ventilation tubes in 4 ears. Symptoms such as autophony, intermittent ear blockage, or aural pressure. Among the 4 ears with a history of ventilation tube insertion: One ear had a completely normal otoscopic examination. Three ears demonstrated mild tympanic membrane sclerosis. One ear showed conductive hearing loss with thresholds of 35 dB (air conduction) and 15 dB (bone conduction). The remaining ears had normal hearing levels. In the other 66 ears in Group 3, 8 ears exhibited sensorineural hearing loss, while 58 ears had normal hearing thresholds. All otoscopic examinations in this subgroup were reported as normal. Interestingly, in 2 additional cases, the contralateral ears initially demonstrated Type A tympanograms but later developed Type Ad patterns during follow-up, after which they were included in the study. Follow-Up Findings Among the 66 ears classified under Group 3, 50 ears were successfully followed up at the 30-day re-evaluation. Comparative analysis of pre- and post-treatment tympanometric values revealed a moderate positive correlation (r = 0.65, p < 0.001), indicating a general reduction in static compliance over time (Fig. 2 ). When the subgroup of non-smoking patients (n = 28 ears) was analyzed independently, a stronger correlation between baseline and follow-up static compliance values was observed (r = 0.72, p < 0.001), reflecting a more consistent trend toward normalization in tympanometric profiles among non-smokers (Fig. 3 ). In terms of tympanometric pattern changes over the follow-up period: 14 out of 50 ears transitioned from Type Ad to Type A tympanograms, with static compliance values falling below 1.6 mL. Three ears developed Type C tympanograms. Across the entire Group 3 cohort (n = 66), Type C tympanograms were ultimately identified in 7 ears, as well as in 3 contralateral ears during subsequent follow-ups. Discussion In this prospective, cross-sectional study, we investigated whether Type Ad tympanometric patterns could be attributed to causes other than well-recognized structural abnormalities such as ossicular disarticulation or tympanic membrane atrophy. Our results suggest that functional factors, especially Eustachian tube dysfunction (ETD), may play a significant role in the emergence of this tympanometric profile, even in the absence of observable anatomical pathology. The reversibility of Type Ad tympanograms in several patients—evidenced by a transition to Type A curves after medical treatment—further supports the hypothesis that non-structural, potentially reversible conditions may contribute to the exaggerated compliance seen in Ad configurations. This finding holds clinical importance, as it may prevent unnecessary surgical interventions or misclassification of benign findings. Our observations agree with earlier reports in the literature. For instance, Ogisi (1988) evaluated 431 Nigerian school-entry children and found Type Ad tympanograms in 40 subjects, 35 of whom had normal otoscopic examinations, suggesting the possibility of subclinical or functional causes ( 5 ). Similarly, Kirfi et al. identified Type Ad patterns in approximately 4% of prisoners, proposing repeated trauma (e.g., slapping) as a contributing factor ( 6 ). However, we propose an alternative explanation for these findings: shared environmental conditions, including crowded living spaces, smoking, and recurrent upper respiratory infections, could have induced ETD, leading to transient Ad tympanograms. Our study also aligns with the findings of Tomiazzi et al., who demonstrated a progressive increase in the incidence of Type Ad tympanograms across groups exposed to pesticides, tobacco smoke, or both. Their results implied a cumulative irritant effect on the upper respiratory tract and middle ear ( 7 ). Pesticide exposure has been linked to increased prevalence of allergic rhinitis, which is a known risk factor for ETD ( 8 , 9 ). Furthermore, chronic tobacco use impairs mucociliary clearance and Eustachian tube function, contributing to middle ear pressure dysregulation ( 10 , 11 ). These mechanisms are supported by our subgroup analysis, where non-smokers demonstrated more consistent normalization of tympanometric curves after treatment. Additionally, patulous Eustachian tube (PET), which is sometimes associated with allergic rhinitis and smoking, has been documented to produce atypical tympanometric responses ( 12 ). Another important factor is nasopharyngeal reflux, which has been implicated in ETD pathogenesis via mucosal irritation and peri tubal inflammation ( 13 ). Consistent with this, a notable proportion of our patients with Type Ad tympanograms reported reflux symptoms, smoking, or nasal allergy, but had no structural abnormalities on otoscopy or imaging. Tuncer et al. observed a higher incidence of Type Ad curves among flight attendants and pilot candidates, likely due to barometric pressure fluctuations and increased susceptibility to upper respiratory tract irritation ( 14 ). Considering that flight crew members are also known to have elevated rates of rhinosinusitis and allergic conditions ( 15 ), it is plausible that transient ETD is responsible for these findings rather than fixed ossicular or tympanic pathology. Long-term follow-up studies further reinforce the potential reversibility of tympanometric abnormalities. In a study by Daly et al., children who had undergone ventilation tube insertion exhibited variable tympanometric outcomes over eight years, ranging from permanent atrophic changes to complete normalization ( 16 ). Similarly, in our cohort, several ears with prior ventilation tube history exhibited normal tympanometry and hearing, supporting the heterogeneous nature of tympanic membrane recovery. Interestingly, a study on osteogenesis imperfecta (OI) patients reported similar distributions of Type A, As, and Ad tympanograms in ears both with and without hearing loss. There was no significant correlation between thin, translucent tympanic membranes and Type Ad curves, highlighting the need for more nuanced interpretation ( 17 ). Moreover, otomicroscopy alone may not be sufficient for detecting subtle middle ear pathology, as demonstrated in animal models of myringosclerosis ( 18 ). These findings suggest that functional and histological evaluations may be necessary when tympanometry results are discordant with clinical observations. The reduction in static compliance over time, particularly among non-smoking patients, suggests that some Type Ad tympanograms represent a transient functional state rather than a permanent structural defect. This reinforces the importance of identifying modifiable contributors such as nasal inflammation, ETD, or reflux, and implementing appropriate medical management before labeling the tympanogram as pathologic. A potential physiological explanation involves surfactants secreted by the respiratory mucosa, which facilitate Eustachian tube opening and middle ear pressure regulation. During inflammation, altered surfactant dynamics and peritubal edema may disrupt normal Eustachian tube function, leading to temporary increases in tympanic membrane compliance ( 19 ). This mechanism could underlie many of the reversible Ad tympanograms observed in our study. Support for a multifactorial etiology also comes from reports of Type Ad tympanograms in diverse patient populations, including those with HIV infection ( 20 ), cleft palate ( 21 ), elderly individuals ( 22 ), rheumatoid arthritis ( 23 ), and Stickler syndrome ( 24 ). These conditions are associated with a wide range of systemic and localized pathologies, further emphasizing the non-specific nature of the Type Ad curve. Although our study also included patients with confirmed tympanic membrane atrophy (Group 2), tympanometric values in that group remained stable over time, suggesting that the tympanometric configuration reflected a structural, non-reversible pattern. In contrast, the more variable tympanometric profiles observed in Group 3—especially in response to treatment—support a functional and reversible etiology. Importantly, when chronic smokers were excluded from analysis, the correlation between pre- and post-treatment compliance values became stronger, suggesting that smoking may impair the recovery potential of the middle ear system. Gastroesophageal reflux may exert a similar effect through repeated exposure of the nasopharynx and Eustachian tube orifices to acidic contents, contributing to chronic mucosal dysfunction. Although the benefit of antihistamines in treating ETD remains controversial ( 25 ), the normalization of tympanograms in 14 ears following medical management in our cohort provides real-world support for their selective use in specific patient populations. Finally, the frequent occurrence of Type C tympanograms in both study ears and contralateral ears during follow-up lends additional support to the concept that transient middle ear pressure dysregulation—particularly due to ETD—can mimic or evolve into a Type Ad pattern, especially in the absence of structural abnormalities. Conclusion Traditionally, Type Ad tympanograms have been regarded as hallmark indicators of irreversible middle ear pathologies, such as ossicular chain discontinuity or tympanic membrane atrophy. However, the findings of this study provide compelling evidence that the Ad pattern may also occur in patients with intact middle ear structures, normal otoscopic findings, and preserved hearing thresholds. A noteworthy proportion of patients in our cohort demonstrated conversion from Type Ad to Type A tympanograms following medical management targeting reversible etiologies, such as Eustachian tube dysfunction (ETD), nasal mucosal inflammation, or gastroesophageal reflux. This observed reversibility supports the concept that functional or transient alterations in middle ear pressure regulation—rather than fixed structural defects—may underlie certain cases of Ad tympanograms. Our findings emphasize the importance of clinical context when interpreting tympanometric results. In patients presenting with Type Ad curves in the absence of hearing loss or abnormal otoscopic signs, clinicians should consider potential non-structural etiologies, particularly in the presence of symptoms like aural fullness, intermittent ear blockage, or autophony. In such cases, a trial of medical therapy and longitudinal follow-up may help to distinguish between transient dysfunction and permanent anatomical damage. Furthermore, environmental and clinical factors—including nasal congestion, allergic rhinitis, tobacco use, and prior middle ear interventions—appear to influence tympanic membrane compliance and middle ear ventilation, potentially leading to misleading tympanometric interpretations if evaluated in isolation. In conclusion, this study advocates for a more nuanced and integrative approach to the interpretation of Type Ad tympanograms. Recognizing the potential for functional contributors and reversibility may prevent unnecessary surgical referrals and improve diagnostic accuracy. Future investigations should aim to characterize the underlying pathophysiological mechanisms, identify predictive clinical markers, and evaluate treatment responses in patients with atypical tympanometric patterns. Such efforts may ultimately refine our understanding of middle ear mechanics and enhance the precision of otologic care. Declarations Acknowledgments The authors would like to express their sincere gratitude to Dr. Serdar Ulus for his valuable assistance with the statistical analysis. Special thanks are also extended to audiologists Esra Kocaman and Zehra Demirtaş for their contributions in conducting the audiological assessments. Source of Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Conflict of Interest The authors declare that they have no competing interests related to the content of this study. Ethical Approval & Informed Consent Ethical approval for this study was obtained from the Institutional Review Board of Hamidiye Medical Faculty, under protocol number HNEAH-KAEK2023/217/4350 . 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Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 08 Dec, 2025 Reviews received at journal 06 Dec, 2025 Reviewers agreed at journal 22 Nov, 2025 Reviews received at journal 20 Nov, 2025 Reviewers agreed at journal 18 Nov, 2025 Reviewers invited by journal 12 Nov, 2025 Editor assigned by journal 24 Sep, 2025 Submission checks completed at journal 24 Sep, 2025 First submitted to journal 22 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7677560","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":549193148,"identity":"266b632c-f774-4473-9878-e74f3cf5f81d","order_by":0,"name":"Sergul Ulus Evecan","email":"","orcid":"","institution":"University of Health Sciences, Sultan 2. 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Abdulhamid Han Research and Training Hospital","correspondingAuthor":false,"prefix":"","firstName":"Orhan","middleName":"","lastName":"Bozkus","suffix":""},{"id":549193151,"identity":"640837d5-503e-4c83-bd5f-e13df72f7005","order_by":3,"name":"Yavuz Aslan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYBADGTDJUwEkmJkbiNLCAyHPgLQwkqKFtw1EEtBicPyMmeSPmjoe/tkNrBvezquN5m8HavlRsQ23ljM5ZhISxw7zSNw5wHZz7rbjuTMOMzYw9py5jVvLgbQ0CQO2AzwMNxLYbvNuO5bbANTCzNiGR8v5Z2kSCf/qeOTBWuYcy51PUMuN5GMSB9uYeQzAWhpqcjcQ0iJ54/Fhy8a+wzyGNxLbbs45diB3I1DLQXx+4Tuf2Hjzx7c6OTmgdTfe1NTlzjt/+OCDHxW4tSgcgDPB0XEYzDyATSkMyDeg8uvwKR4Fo2AUjIIRCgCoNV+v/ZskwwAAAABJRU5ErkJggg==","orcid":"","institution":"University of Health Sciences, Sultan 2. Abdulhamid Han Research and Training Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yavuz","middleName":"","lastName":"Aslan","suffix":""},{"id":549193152,"identity":"846b44ec-621f-456e-beb9-b125d900f54d","order_by":4,"name":"Mustafa Emrah Kinal","email":"","orcid":"","institution":"University of Health Sciences, Sultan 2. Abdulhamid Han Research and Training Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"Emrah","lastName":"Kinal","suffix":""},{"id":549193153,"identity":"a17717fd-8f58-40ad-9de9-62c9c26167e2","order_by":5,"name":"Ibrahim Engin Cekin","email":"","orcid":"","institution":"University of Health Sciences, Sultan 2. Abdulhamid Han Research and Training Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ibrahim","middleName":"Engin","lastName":"Cekin","suffix":""}],"badges":[],"createdAt":"2025-09-22 13:53:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7677560/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7677560/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":96709758,"identity":"fb79e255-c9bc-4ff5-b6d1-88636652f5de","added_by":"auto","created_at":"2025-11-25 10:09:37","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":237641,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.docx","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/5f067bacdf88b375e5f7e138.docx"},{"id":96652784,"identity":"103dff4d-424e-4af0-a499-8e04d080beaf","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8117,"visible":true,"origin":"","legend":"","description":"","filename":"22afa2d6d4ba4889bcfedc4d4dff948e.json","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/571e4c24f627d83f6e5c9498.json"},{"id":96709890,"identity":"419fb2f4-41da-4ed4-972b-e4d2a5d68659","added_by":"auto","created_at":"2025-11-25 10:09:46","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":69409,"visible":true,"origin":"","legend":"","description":"","filename":"22afa2d6d4ba4889bcfedc4d4dff948e1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/f694fcf722dc6029a8d02a21.xml"},{"id":96709705,"identity":"67822dc7-ac4b-41a5-a2d9-ce42a9e701cf","added_by":"auto","created_at":"2025-11-25 10:09:33","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":25499,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/56ac03886773307bc1e14173.png"},{"id":96652782,"identity":"fa14760e-a83e-4fba-919c-6e1943c2d6fc","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":38893,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/e030a1ed63ff2520bd8bdfec.png"},{"id":96652786,"identity":"ca551a74-4078-4a4c-a624-f270d1c7590e","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70155,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/8641d006fdc1aca7b6090224.png"},{"id":96652787,"identity":"1e8f379d-400a-4a7e-970c-dd41e3ab9c52","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"xml","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":67666,"visible":true,"origin":"","legend":"","description":"","filename":"22afa2d6d4ba4889bcfedc4d4dff948e1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/9a209500a891285ccf7c67f9.xml"},{"id":96652789,"identity":"73b8cd80-1391-453f-a73e-ea2b36a7712c","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"html","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":75717,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/f57cc3da866b6239387021cf.html"},{"id":96652780,"identity":"305cbd98-5ed0-4b58-b878-7c168eb9ae2b","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":51267,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDistribution of Hearing Status and Tympanometric Patterns in Group 2 Patients with Tympanic Membrane Atrophy.\u003c/strong\u003e\u003cbr\u003e\nThe figure presents the distribution of hearing types (normal hearing, sensorineural, mixed, and conductive hearing loss) in Group 2, alongside tympanometric patterns observed during initial and follow-up examinations. One ear developed a Type C tympanogram during follow-up, while others retained similar static compliance values.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/c41137d428d71af3da3223e4.jpeg"},{"id":96652781,"identity":"70a5fe28-1261-4b77-9a9c-86164a11d77c","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":79331,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eComparison of Static Compliance Values in Group 3 Before and After Medical Treatment.\u003c/strong\u003e\u003cbr\u003e\nThe scatter plot shows static compliance values for 50 ears with Type Ad tympanograms (Group 3) before and after treatment. A moderate positive correlation was found (r = 0.65, p \u0026lt; 0.001), indicating a general trend toward reduced compliance following treatment.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/78c8d2f98ff59acaa3ac4c56.jpeg"},{"id":96652788,"identity":"ae8327e8-31fd-4d64-8668-a3f1831cd516","added_by":"auto","created_at":"2025-11-24 16:36:02","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":69132,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of Smoking on Tympanometric Changes in Group 3: Subgroup Analysis of Non-Smokers.\u003c/strong\u003e\u003cbr\u003e\nThis figure illustrates the static compliance values before and after treatment in the subgroup of non-smoking patients (n = 28), revealing a stronger positive correlation (r = 0.72, p \u0026lt; 0.001) compared to the overall group. This suggests a more consistent improvement in non-smokers.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/14de4e30cc08cf978f31f949.jpeg"},{"id":96712741,"identity":"102156c7-4459-46df-a350-e7dc2ca5c41b","added_by":"auto","created_at":"2025-11-25 10:16:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":900737,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7677560/v1/628fc46b-76ac-4d5d-ab95-36a00a37d994.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eType Ad Tympanogram: Is There More Than Known?\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTympanometry is a non-invasive and objective diagnostic technique that provides essential information about middle ear function by assessing the compliance of the tympanic membrane and ossicular chain in response to changes in external ear canal pressure. It plays a pivotal role in the differential diagnosis of conductive hearing loss, middle ear pathologies, and Eustachian tube dysfunction (ETD), and is routinely used in combination with pure-tone audiometry in otologic practice (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAmong the established classification systems, the Jerger classification is most widely used. In this system, a Type Ad tympanogram is characterized by excessively high static acoustic compliance (\u0026gt;\u0026thinsp;1.6 mL), with normal middle ear pressure and canal volume, which typically suggests ossicular chain discontinuity or tympanic membrane atrophy, as seen in healed perforations or thin, hypermobile membranes (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). However, recent clinical observations challenge this traditional view, as Type Ad tympanograms are increasingly encountered in patients without discernible structural abnormalities on otoscopic examination or imaging studies (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn some cases, these tympanometric findings occur in the absence of hearing loss, leading to diagnostic uncertainty and possible underestimation of clinical relevance. This raises the question: \u003cem\u003eCould functional or reversible conditions mimic the Ad tympanometric pattern typically associated with mechanical pathology?\u003c/em\u003e\u003c/p\u003e\u003cp\u003eEmerging evidence suggests that Eustachian tube dysfunction (ETD), nasopharyngeal congestion, reflux-related inflammation, and smoking-related mucosal changes may transiently alter middle ear pressure regulation and tympanic membrane mechanics, thereby producing Type Ad-like curves in the absence of anatomical disruption (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Nonetheless, data supporting these alternative mechanisms are limited, and the clinical significance of Type Ad tympanograms in such populations remains underexplored.\u003c/p\u003e\u003cp\u003eTherefore, the present study was designed to investigate clinical and audiological characteristics of patients with Type Ad tympanograms, with particular attention to functional etiologies, including ETD. We aimed to evaluate whether non-mechanical conditions may account for this tympanometric profile, and to observe whether these patterns demonstrate reversibility following medical treatment or natural resolution.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThis prospective observational study was conducted at the otolaryngology outpatient clinic of a tertiary referral hospital between December 2023 and December 2024. The study protocol was reviewed and approved by the Institutional Review Board and Ethics Committee of Hamidiye Medical Faculty (Approval Number: HNEAH-KAEK2023/217/4350). All procedures adhered to the ethical principles outlined in the Declaration of Helsinki (1975, revised in 2008), and written informed consent was obtained from all participants or their legal guardians.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatient Selection and Inclusion Criteria\u003c/h2\u003e\u003cp\u003ePatients of both sexes who presented to the clinic during the study period and were found to have a Type Ad tympanometric curve in at least one ear were included. A total of 64 patients (40 males and 24 females) between 8 and 68 years of age (mean age: 42.59\u0026thinsp;\u0026plusmn;\u0026thinsp;15.26 years) were enrolled. In total, 90 ears demonstrating Type Ad tympanograms were subjected to detailed clinical and audiological evaluation.\u003c/p\u003e\u003cp\u003eExclusion criteria included:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eA history of otologic surgery (except ventilation tube insertion)\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePresence of tympanic membrane perforation\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eExternal auditory canal abnormalities\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAcute otitis media or otitis externa at the time of examination\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eClinical Assessment\u003c/h3\u003e\n\u003cp\u003eEach participant underwent a comprehensive otolaryngologic examination, including:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eOtoscopy to assess tympanic membrane integrity and appearance\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eNasal endoscopy and nasopharyngoscopy to evaluate signs of mucosal inflammation or anatomical variations suggestive of Eustachian tube dysfunction (ETD)\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAssessment of allergy symptoms, nasal obstruction, and history of gastroesophageal reflux or smoking\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eDemographic data, medical history, and presenting complaints (such as ear fullness, autophony, aural pressure, or tinnitus) were documented using a standardized data collection form.\u003c/p\u003e\n\u003ch3\u003eAudiological Assessment\u003c/h3\u003e\n\u003cp\u003ePure-tone audiometry was performed in a sound-treated booth by certified audiologists using calibrated IAC audiometers (Industrial Acoustic Company Inc., New York) and TDH-39P headphones. Air-conduction thresholds were obtained at 0.5, 1, 2, and 4 kHz, while bone-conduction thresholds were measured at 0.5, 1, and 2 kHz when necessary. The pure-tone average (PTA) was calculated from thresholds at 0.5, 1, and 2 kHz. Hearing thresholds between 0\u0026ndash;25 dB HL were considered normal, including the upper limit of 25 dB. An air-bone gap\u0026thinsp;\u0026le;\u0026thinsp;10 dB with elevated air-conduction thresholds was interpreted as sensorineural hearing loss, in accordance with established audiological criteria [7].\u003c/p\u003e\n\u003ch3\u003eTympanometric Evaluation\u003c/h3\u003e\n\u003cp\u003eTympanometry was conducted using a calibrated Interacoustics AT-235 impedance audiometer (Interacoustics, Assens, Denmark), employing a 226 Hz probe tone and a pressure sweep from +\u0026thinsp;200 to \u0026minus;\u0026thinsp;400 daPa, performed in a positive-to-negative direction. The Jerger classification system was used to define tympanometric patterns. Type Ad tympanograms were identified based on the following criteria:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eMiddle ear pressure between \u0026minus;\u0026thinsp;100 to +\u0026thinsp;50 daPa\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eStatic acoustic compliance\u0026thinsp;\u0026gt;\u0026thinsp;1.6 mL, including exactly 1.6 mL\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eBoth ipsilateral and contralateral acoustic reflexes were tested and recorded. These tests provided supplementary information to rule out middle ear effusion and ossicular chain fixation.\u003c/p\u003e\n\u003ch3\u003eTreatment and Follow-Up Protocol\u003c/h3\u003e\n\u003cp\u003ePatients with nasal allergies, seromucous rhinorrhea, or nasopharyngeal inflammation were prescribed oral antihistamines for a minimum of 30 days, and antibiotics were added when signs of bacterial infection were present. Patients with suspected ETD received education on nasal hygiene and pressure equalization techniques. Those with confirmed ossicular discontinuity were excluded from the follow-up arm of the study, as their tympanometric findings were considered permanent.\u003c/p\u003e\u003cp\u003eAll remaining patients were invited for re-evaluation 30 days after initial diagnosis. At follow-up, patients were re-assessed with otoscopy, audiometry, and tympanometry. Additional follow-up visits were scheduled for individuals showing:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003ePersistent otologic symptoms (e.g., aural fullness, pressure)\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eEvolution into Type C or Type B tympanograms\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eClinical deterioration or need for ventilation tube placement\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eThis longitudinal approach allowed for the monitoring of tympanometric reversibility, particularly in cases where no structural abnormalities were observed at baseline.\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eDescriptive statistical analyses were conducted to summarize the demographic, clinical, and audiological characteristics of the study population. Categorical variables were expressed as frequencies and percentages, while continuous variables were presented as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations (SD).\u003c/p\u003e\u003cp\u003eThe Kolmogorov\u0026ndash;Smirnov test was employed to assess the normality of distribution for continuous data. Based on the distribution characteristics, appropriate comparative tests were selected. For paired nonparametric variables, the Wilcoxon signed-rank test was applied, whereas paired samples t-tests were used for parametric paired data.\u003c/p\u003e\u003cp\u003eTo evaluate the relationships between continuous variables, correlation analyses were performed using Pearson\u0026rsquo;s correlation coefficient for normally distributed variables and Spearman\u0026rsquo;s rank-order correlation coefficient for non-normally distributed variables.\u003c/p\u003e\u003cp\u003eAll statistical analyses were conducted using SPSS for Windows, version 15.0 (SPSS Inc., Chicago, IL, USA). A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered indicative of statistical significance throughout the analyses.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eAt the time of initial presentation, patients reported a variety of otologic and nasal complaints. The most frequently reported symptom was ear fullness, noted in 23 patients (25.6%). This was followed by otalgia in 12 patients (13.3%), tinnitus or other ear noises in 11 patients (12.2%), nasal congestion in 11 patients (12.2%), hearing loss in 8 patients (8.9%), and a sensation of pressure in the ear in 8 patients (8.9%). In 17 ears (18.9%), the Type Ad tympanogram was incidentally detected in the contralateral ear during routine evaluation, without any associated complaint.\u003c/p\u003e\u003cp\u003eOf the 90 ears evaluated, the distribution between right and left ears was equal\u0026mdash;45 right ears and 45 left ears. Regarding comorbid medical conditions, 59 ears (65.6%) were from patients without any chronic illness or regular medication use, whereas 31 ears (34.4%) were associated with one or more chronic diseases. The breakdown of these conditions is as follows:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eHypertension was present in 8 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHypothyroidism was documented in 4 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eDiabetes mellitus was found in 3 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eCoronary artery disease was present in 2 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eLaryngopharyngeal reflux and pityriasis versicolor were each noted in 2 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAsthma, bipolar disorder, and colon cancer were each present in 1 ear.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eCombined conditions included diabetes with hypertension in 5 ears, coronary artery disease with hypertension in 1 ear, and coronary artery disease with diabetes in 1 ear.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eWith respect to smoking habits, 28 ears (31.1%) were from individuals who reported smoking more than 15 cigarettes per day. Fifty-six ears (62.2%) belonged to non-smokers, and 6 ears (6.7%) were from patients who had previously smoked but had since quit after prolonged use.\u003c/p\u003e\u003cp\u003eAudiological assessment revealed the following distribution:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eSensorineural hearing loss was identified in 10 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eConductive hearing loss was found in 6 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eMixed hearing loss was present in 4 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe remaining 70 ears demonstrated normal hearing thresholds.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eBased on combined clinical, otoscopic, and audiological findings, all ears were categorized into three groups for further analysis:\u003c/p\u003e\n\u003ch3\u003eGroup 1 – Ossicular Chain Disarticulation (n = 4 ears):\u003c/h3\u003e\n\u003cp\u003eIn this group, ossicular disarticulation was confirmed surgically. Two of the ears had conductive hearing loss, and the other two demonstrated mixed hearing loss, despite appearing normal on otoscopic examination.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eGroup 2 \u0026ndash; Tympanic Membrane Atrophy (n\u0026thinsp;=\u0026thinsp;16 ears):\u003c/h2\u003e\u003cp\u003eThese ears exhibited notable atrophy of the tympanic membrane. Within this group:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eNine ears had normal hearing.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eTwo ears demonstrated sensorineural hearing loss.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eTwo ears showed mixed hearing loss.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThree ears had conductive hearing loss.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eAt the 30-day follow-up, one ear in this group developed a Type C tympanogram, while the remainder maintained similar static compliance values to baseline. During extended observation, four additional ears developed Type C curves, along with six contralateral ears that also shifted to a Type C configuration.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eGroup 3 \u0026ndash; No Structural Pathology / Functional Etiology (n\u0026thinsp;=\u0026thinsp;70 ears):\u003c/h2\u003e\u003cp\u003eThis group consisted of patients without identifiable structural abnormalities but who exhibited clinical signs consistent with Eustachian tube dysfunction (ETD). The common findings in this group included:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003ePresence of serous or seropurulent nasal secretions.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eA medical history of reflux, allergic rhinitis, or smoking.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePrevious insertion of ventilation tubes in 4 ears.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eSymptoms such as autophony, intermittent ear blockage, or aural pressure.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eAmong the 4 ears with a history of ventilation tube insertion:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eOne ear had a completely normal otoscopic examination.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThree ears demonstrated mild tympanic membrane sclerosis.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eOne ear showed conductive hearing loss with thresholds of 35 dB (air conduction) and 15 dB (bone conduction).\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe remaining ears had normal hearing levels.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eIn the other 66 ears in Group 3, 8 ears exhibited sensorineural hearing loss, while 58 ears had normal hearing thresholds. All otoscopic examinations in this subgroup were reported as normal.\u003c/p\u003e\u003cp\u003eInterestingly, in 2 additional cases, the contralateral ears initially demonstrated Type A tympanograms but later developed Type Ad patterns during follow-up, after which they were included in the study.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003eFollow-Up Findings\u003c/h2\u003e\u003cp\u003eAmong the 66 ears classified under Group 3, 50 ears were successfully followed up at the 30-day re-evaluation. Comparative analysis of pre- and post-treatment tympanometric values revealed a moderate positive correlation (r\u0026thinsp;=\u0026thinsp;0.65, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), indicating a general reduction in static compliance over time (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eWhen the subgroup of non-smoking patients (n\u0026thinsp;=\u0026thinsp;28 ears) was analyzed independently, a stronger correlation between baseline and follow-up static compliance values was observed (r\u0026thinsp;=\u0026thinsp;0.72, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), reflecting a more consistent trend toward normalization in tympanometric profiles among non-smokers (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIn terms of tympanometric pattern changes over the follow-up period:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003e14 out of 50 ears transitioned from Type Ad to Type A tympanograms, with static compliance values falling below 1.6 mL.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThree ears developed Type C tympanograms.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAcross the entire Group 3 cohort (n\u0026thinsp;=\u0026thinsp;66), Type C tympanograms were ultimately identified in 7 ears, as well as in 3 contralateral ears during subsequent follow-ups.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this prospective, cross-sectional study, we investigated whether Type Ad tympanometric patterns could be attributed to causes other than well-recognized structural abnormalities such as ossicular disarticulation or tympanic membrane atrophy. Our results suggest that functional factors, especially Eustachian tube dysfunction (ETD), may play a significant role in the emergence of this tympanometric profile, even in the absence of observable anatomical pathology.\u003c/p\u003e\u003cp\u003eThe reversibility of Type Ad tympanograms in several patients\u0026mdash;evidenced by a transition to Type A curves after medical treatment\u0026mdash;further supports the hypothesis that non-structural, potentially reversible conditions may contribute to the exaggerated compliance seen in Ad configurations. This finding holds clinical importance, as it may prevent unnecessary surgical interventions or misclassification of benign findings.\u003c/p\u003e\u003cp\u003eOur observations agree with earlier reports in the literature. For instance, Ogisi (1988) evaluated 431 Nigerian school-entry children and found Type Ad tympanograms in 40 subjects, 35 of whom had normal otoscopic examinations, suggesting the possibility of subclinical or functional causes (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Similarly, Kirfi et al. identified Type Ad patterns in approximately 4% of prisoners, proposing repeated trauma (e.g., slapping) as a contributing factor (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). However, we propose an alternative explanation for these findings: shared environmental conditions, including crowded living spaces, smoking, and recurrent upper respiratory infections, could have induced ETD, leading to transient Ad tympanograms.\u003c/p\u003e\u003cp\u003eOur study also aligns with the findings of Tomiazzi et al., who demonstrated a progressive increase in the incidence of Type Ad tympanograms across groups exposed to pesticides, tobacco smoke, or both. Their results implied a cumulative irritant effect on the upper respiratory tract and middle ear (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Pesticide exposure has been linked to increased prevalence of allergic rhinitis, which is a known risk factor for ETD (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Furthermore, chronic tobacco use impairs mucociliary clearance and Eustachian tube function, contributing to middle ear pressure dysregulation (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). These mechanisms are supported by our subgroup analysis, where non-smokers demonstrated more consistent normalization of tympanometric curves after treatment.\u003c/p\u003e\u003cp\u003eAdditionally, patulous Eustachian tube (PET), which is sometimes associated with allergic rhinitis and smoking, has been documented to produce atypical tympanometric responses (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Another important factor is nasopharyngeal reflux, which has been implicated in ETD pathogenesis via mucosal irritation and peri tubal inflammation (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Consistent with this, a notable proportion of our patients with Type Ad tympanograms reported reflux symptoms, smoking, or nasal allergy, but had no structural abnormalities on otoscopy or imaging.\u003c/p\u003e\u003cp\u003eTuncer et al. observed a higher incidence of Type Ad curves among flight attendants and pilot candidates, likely due to barometric pressure fluctuations and increased susceptibility to upper respiratory tract irritation (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Considering that flight crew members are also known to have elevated rates of rhinosinusitis and allergic conditions (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e), it is plausible that transient ETD is responsible for these findings rather than fixed ossicular or tympanic pathology.\u003c/p\u003e\u003cp\u003eLong-term follow-up studies further reinforce the potential reversibility of tympanometric abnormalities. In a study by Daly et al., children who had undergone ventilation tube insertion exhibited variable tympanometric outcomes over eight years, ranging from permanent atrophic changes to complete normalization (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Similarly, in our cohort, several ears with prior ventilation tube history exhibited normal tympanometry and hearing, supporting the heterogeneous nature of tympanic membrane recovery.\u003c/p\u003e\u003cp\u003eInterestingly, a study on osteogenesis imperfecta (OI) patients reported similar distributions of Type A, As, and Ad tympanograms in ears both with and without hearing loss. There was no significant correlation between thin, translucent tympanic membranes and Type Ad curves, highlighting the need for more nuanced interpretation (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Moreover, otomicroscopy alone may not be sufficient for detecting subtle middle ear pathology, as demonstrated in animal models of myringosclerosis (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). These findings suggest that functional and histological evaluations may be necessary when tympanometry results are discordant with clinical observations.\u003c/p\u003e\u003cp\u003eThe reduction in static compliance over time, particularly among non-smoking patients, suggests that some Type Ad tympanograms represent a transient functional state rather than a permanent structural defect. This reinforces the importance of identifying modifiable contributors such as nasal inflammation, ETD, or reflux, and implementing appropriate medical management before labeling the tympanogram as pathologic.\u003c/p\u003e\u003cp\u003eA potential physiological explanation involves surfactants secreted by the respiratory mucosa, which facilitate Eustachian tube opening and middle ear pressure regulation. During inflammation, altered surfactant dynamics and peritubal edema may disrupt normal Eustachian tube function, leading to temporary increases in tympanic membrane compliance (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). This mechanism could underlie many of the reversible Ad tympanograms observed in our study.\u003c/p\u003e\u003cp\u003eSupport for a multifactorial etiology also comes from reports of Type Ad tympanograms in diverse patient populations, including those with HIV infection (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e), cleft palate (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e), elderly individuals (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e), rheumatoid arthritis (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e), and Stickler syndrome (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). These conditions are associated with a wide range of systemic and localized pathologies, further emphasizing the non-specific nature of the Type Ad curve.\u003c/p\u003e\u003cp\u003eAlthough our study also included patients with confirmed tympanic membrane atrophy (Group 2), tympanometric values in that group remained stable over time, suggesting that the tympanometric configuration reflected a structural, non-reversible pattern. In contrast, the more variable tympanometric profiles observed in Group 3\u0026mdash;especially in response to treatment\u0026mdash;support a functional and reversible etiology. Importantly, when chronic smokers were excluded from analysis, the correlation between pre- and post-treatment compliance values became stronger, suggesting that smoking may impair the recovery potential of the middle ear system.\u003c/p\u003e\u003cp\u003eGastroesophageal reflux may exert a similar effect through repeated exposure of the nasopharynx and Eustachian tube orifices to acidic contents, contributing to chronic mucosal dysfunction. Although the benefit of antihistamines in treating ETD remains controversial (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e), the normalization of tympanograms in 14 ears following medical management in our cohort provides real-world support for their selective use in specific patient populations.\u003c/p\u003e\u003cp\u003eFinally, the frequent occurrence of Type C tympanograms in both study ears and contralateral ears during follow-up lends additional support to the concept that transient middle ear pressure dysregulation\u0026mdash;particularly due to ETD\u0026mdash;can mimic or evolve into a Type Ad pattern, especially in the absence of structural abnormalities.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eTraditionally, Type Ad tympanograms have been regarded as hallmark indicators of irreversible middle ear pathologies, such as ossicular chain discontinuity or tympanic membrane atrophy. However, the findings of this study provide compelling evidence that the Ad pattern may also occur in patients with intact middle ear structures, normal otoscopic findings, and preserved hearing thresholds.\u003c/p\u003e\u003cp\u003eA noteworthy proportion of patients in our cohort demonstrated conversion from Type Ad to Type A tympanograms following medical management targeting reversible etiologies, such as Eustachian tube dysfunction (ETD), nasal mucosal inflammation, or gastroesophageal reflux. This observed reversibility supports the concept that functional or transient alterations in middle ear pressure regulation\u0026mdash;rather than fixed structural defects\u0026mdash;may underlie certain cases of Ad tympanograms.\u003c/p\u003e\u003cp\u003eOur findings emphasize the importance of clinical context when interpreting tympanometric results. In patients presenting with Type Ad curves in the absence of hearing loss or abnormal otoscopic signs, clinicians should consider potential non-structural etiologies, particularly in the presence of symptoms like aural fullness, intermittent ear blockage, or autophony. In such cases, a trial of medical therapy and longitudinal follow-up may help to distinguish between transient dysfunction and permanent anatomical damage.\u003c/p\u003e\u003cp\u003eFurthermore, environmental and clinical factors\u0026mdash;including nasal congestion, allergic rhinitis, tobacco use, and prior middle ear interventions\u0026mdash;appear to influence tympanic membrane compliance and middle ear ventilation, potentially leading to misleading tympanometric interpretations if evaluated in isolation.\u003c/p\u003e\u003cp\u003eIn conclusion, this study advocates for a more nuanced and integrative approach to the interpretation of Type Ad tympanograms. Recognizing the potential for functional contributors and reversibility may prevent unnecessary surgical referrals and improve diagnostic accuracy. Future investigations should aim to characterize the underlying pathophysiological mechanisms, identify predictive clinical markers, and evaluate treatment responses in patients with atypical tympanometric patterns. Such efforts may ultimately refine our understanding of middle ear mechanics and enhance the precision of otologic care.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to express their sincere gratitude to\u0026nbsp;Dr. Serdar Ulus\u0026nbsp;for his valuable assistance with the\u0026nbsp;statistical analysis. Special thanks are also extended to\u0026nbsp;audiologists Esra Kocaman and Zehra Demirtaş\u0026nbsp;for their contributions in conducting the\u0026nbsp;audiological assessments.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSource of Funding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests related to the content of this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval \u0026amp; Informed Consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval for this study was obtained from the Institutional Review Board of Hamidiye Medical Faculty, under protocol number \u003cstrong\u003eHNEAH-KAEK2023/217/4350\u003c/strong\u003e. All procedures performed were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Declaration of Helsinki and its later amendments. Informed consent was obtained from all participants or their legal guardians.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKei J, Sockalingam R, Holloway C, Agyik A, Brinin C, Baine D (2003) Transient evoked otoacoustic emissions in adults: a comparison between two test protocols. J Am Acad Audiol 14(10):563\u0026ndash;573\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHamid M, Brookler KH (2007) Tympanometry. \u003cem\u003eEar, Nose \u0026amp; Throat Journal, 86\u003c/em\u003e(11), 668\u0026ndash;669\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHolt GR, Watkins TM, Yoder MG (1982) Assessment of tympanometry abnormalities of the tympanic membrane. Am J Otolaryngol 3(2):112\u0026ndash;116\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOgisi FO (1988) Impedance screening for otitis media with effusion in Nigerian children. J Laryngology Otology 102(11):986\u0026ndash;988\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePezzoli M, Lofaro D, Oliva A, Orione M, Cupi D, Albera A et al (2017) Effects of smoking on Eustachian tube and hearing. Int Tinnitus J 21(2):98\u0026ndash;103\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhen Z, Zhao T, Wang Q, Zhang J, Zhong Z (2022) Laryngopharyngeal reflux as a potential cause of Eustachian tube dysfunction in patients with otitis media with effusion. Front Neurol 13:1024743. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fneur.2022.1024743\u003c/span\u003e\u003cspan address=\"10.3389/fneur.2022.1024743\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKatz J, Chasin M, English K, Hood LJ, Tillery KL (2015) Handbook of Clinical Audiology, 7th edn. Wolters Kluwer Health\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSlager RE, Poole JA, LeVan TD, Sandler DP, Alavanja MC, Hoppin JA (2009) Rhinitis associated with pesticide exposure among commercial pesticide applicators in the Agricultural Health Study. Occup Environ Med 66(11):718\u0026ndash;724\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKoureas M, Rachiotis G, Tsakalof A, Hadjichristodoulou C (2017) Increased frequency of rheumatoid arthritis and allergic rhinitis among pesticide sprayers and associations with pesticide use. Int J Environ Res Public Health 14(8):865\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePezzoli M, Lofaro D, Oliva A et al (2017) Effects of smoking on Eustachian tube and hearing. Int Tinnitus J 21(2):98\u0026ndash;103\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePatel MA, Mener DJ, Garcia-Esquinas E et al (2016) Tobacco smoke exposure and Eustachian tube disorders in US children and adolescents. PLoS ONE 11(10):e0163926\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWard BK, Chao WC, Abiola G et al (2019) Twelve-month outcomes of Eustachian tube procedures for management of patulous Eustachian tube dysfunction. Laryngoscope 129(1):222\u0026ndash;228\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhen Z, Zhao T, Wang Q et al (2022) Laryngopharyngeal reflux as a potential cause of Eustachian tube dysfunction in patients with otitis media with effusion. Front Neurol 13:1024743\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTuncer MM, Babakurban ST, Aydin E (2016) Middle ear resonance frequency in pilots and pilot candidates. Aerosp Med Hum Perform 87(10):876\u0026ndash;881\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBeatty AL, Haight TJ, Redberg RF (2011) Associations between respiratory illnesses and secondhand smoke exposure in flight attendants: A cross-sectional analysis of the Flight Attendant Medical Research Institute Survey. Environ Health 10(1):81\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDaly KA, Hunter LL, Lindgren BR et al (2003) Chronic otitis media with effusion sequelae in children treated with tubes. Archives Otolaryngology\u0026ndash;Head Neck Surg 129(5):517\u0026ndash;522\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSwinnen FK, Dhooge IJ, Coucke PJ et al (2012) Audiologic phenotype of osteogenesis imperfecta: Use in clinical differentiation. Otolaryngology\u0026ndash;Head Neck Surg 33(2):115\u0026ndash;122\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSantos PF, Leal MC, Peixoto C et al (2005) Otomicroscopic and histologic findings of induced myringosclerosis in rats: A critical study of an experimental model. Braz J Otorhinolaryngol 71(5):668\u0026ndash;674\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eArs B, Dirckx J (2016) Eustachian tube function. Otolaryngol Clin North Am 49(5):1121\u0026ndash;1133\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSebothoma B, Khoza-Shangase K (2018) A comparison between video otoscopy and standard tympanometry findings in adults living with HIV in South Africa. South Afr J Commun Disord 65(1):e1\u0026ndash;e7\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNarayanan DS, Pandian SS, Murugesan S, Kumar R (2013) The incidence of secretory otitis media in cases of cleft palate. J Clin Diagn Res 7(7):1383\u0026ndash;1386\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi J, Zhao H, Huang B et al (2018) A survey on hearing acuity of centenarians in Hainan Province. J Otology 13(4):135\u0026ndash;137\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOzcan M, Karakuş MF, G\u0026uuml;nd\u0026uuml;z OH et al (2002) Hearing loss and middle ear involvement in rheumatoid arthritis. Rheumatol Int 22(1):16\u0026ndash;19\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSzymko-Bennett YM, Mastroianni MA, Shotland LI et al (2001) Auditory dysfunction in Stickler syndrome. Archives Otolaryngology\u0026ndash;Head Neck Surg 127(9):1061\u0026ndash;1068\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJuszczak HM, Loftus PA (2020) Role of allergy in Eustachian tube dysfunction. Curr Allergy Asthma Rep 20(10):54\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-egyptian-journal-of-otolaryngology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [The Egyptian Journal of Otolaryngology](https://ejo.springeropen.com/)","snPcode":"43163","submissionUrl":"https://submission.springernature.com/new-submission/43163/3","title":"The Egyptian Journal of Otolaryngology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Eustachian tube dysfunction, middle ear effusion, tympanic membrane, tympanometry, ossicular chain","lastPublishedDoi":"10.21203/rs.3.rs-7677560/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7677560/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective:\u003c/h2\u003e\u003cp\u003eThe aim of this study was to investigate the clinical and audiological characteristics of patients with Type Ad tympanograms and to determine whether Eustachian tube dysfunction (ETD) or other non-mechanical factors might contribute to the development of this tympanometric pattern in the absence of structural middle ear pathology.\u003c/p\u003e\u003ch2\u003eMaterials and Methods:\u003c/h2\u003e\u003cp\u003eThis prospective observational study included 64 patients who presented to the otolaryngology outpatient clinic of a tertiary care hospital between December 2023 and December 2024 and were found to have a Type Ad tympanogram in at least one ear. All participants underwent a comprehensive otolaryngologic evaluation, including otoscopy, nasal endoscopy, nasopharyngoscopy, and pure-tone audiometry. Tympanometric measurements were performed using standardized classification criteria. Based on clinical, audiological, and otoscopic findings, ears were categorized into three groups: ossicular disarticulation, tympanic membrane atrophy, and cases without structural abnormalities, the latter being suggestive of functional etiologies such as ETD.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eA total of 90 ears with Type Ad tympanograms were evaluated. Among these, 70 ears demonstrated no structural pathology but had clinical features suggestive of ETD, including nasal congestion, allergic symptoms, or a history of reflux and smoking. Notably, 14 of these ears transitioned to Type A tympanograms following medical treatment, and 7 ears developed Type C tympanograms during follow-up. These findings indicate a potential role of functional, reversible mechanisms such as impaired middle ear ventilation in the generation of Type Ad tympanograms.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eAlthough Type Ad tympanograms are classically associated with ossicular chain discontinuity or tympanic membrane atrophy, this study demonstrates that ETD and other non-structural factors may also produce this tympanometric pattern. Recognizing these functional contributors is essential to avoid diagnostic errors and guide appropriate treatment. Longitudinal evaluation and medical management may aid in distinguishing transient dysfunction from irreversible structural abnormalities.\u003c/p\u003e","manuscriptTitle":"Type Ad Tympanogram: Is There More Than Known?","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-24 16:35:57","doi":"10.21203/rs.3.rs-7677560/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-08T08:43:08+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-06T22:02:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"305532558683287851401489818127044828135","date":"2025-11-22T15:59:53+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-20T20:43:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"196498976649691337235252232192622294717","date":"2025-11-18T11:39:18+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-12T11:03:50+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-24T10:11:17+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-24T10:10:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"The Egyptian Journal of Otolaryngology","date":"2025-09-22T10:28:09+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-egyptian-journal-of-otolaryngology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [The Egyptian Journal of Otolaryngology](https://ejo.springeropen.com/)","snPcode":"43163","submissionUrl":"https://submission.springernature.com/new-submission/43163/3","title":"The Egyptian Journal of Otolaryngology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ab29c263-3a07-4b2e-a123-40f6b92279d3","owner":[],"postedDate":"November 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-01-01T13:38:34+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-24 16:35:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7677560","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7677560","identity":"rs-7677560","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}