Salient features of task-irrelevant continuous speech distort subjective time

Computational models of auditory salience predict that acoustic change and divergence from prediction increase the salience of sound streams. Confirming these predictions, prior research has shown that acoustic change and unpredictable sound features are linked to increases in physiological arousal and disruption of concurrent task performance. However, it remains unclear whether linguistic features, such as phonemic and lexical/semantic surprisal, help drive attentional orienting, or whether instead attentional capture takes place prior to linguistic analysis. To address this question, we introduce a new technique for assessing attentional capture by naturalistic task-irrelevant speech. In this paradigm participants tap to a metronome while ignoring a spoken passage from an audiobook. Salient features of the task-irrelevant speech capture attention, increase arousal, and expand subjective time, leading to shifts in tap timing. We show that distortions of subjective time are driven not only by acoustic change but also by phonemic surprisal. Thus, attentional orienting to sound takes place after the initial stages of linguistic analysis.