Noise increases listening effort in normal-hearing young adults, regardless of working memory capacity (preprint, Dec 2018)

As listening conditions worsen (e.g., background noise increases), additional cognitive effort is required to process speech. The existing literature is mixed on whether and how cognitive traits like working memory capacity moderate the amount of effort that listeners must expend to successfully understand speech. Here, we validate a dual-task measure of listening effort (Experiment 1) and demonstrate that, for normal-hearing young adults, effort increases as listening conditions worsen, but working memory capacity is unrelated to the amount of effort expended (Experiment 2). We propose that previous research may have overestimated the relationship between listening effort and working memory capacity by measuring listening effort using recall-based tasks, but the relationship between the two disappears when using a measure of listening effort that does not require recall. These results suggest caution in making the general assumption that working memory capacity is related to the amount of effort expended during a listening task.