Listening effort in a realistic multi-talker speech comprehension test
Introduction: Current speech comprehension assessments cannot provide a sensitive and comprehensive measure of listeners' real-life speech comprehension ability. Furthermore, they do not assess listeners’ listening effort, an important index during speech comprehension. Therefore, this study aimed to develop and evaluate a realistic multi-talker speech comprehension test and then examine the correlation between perceived listening effort and the outcome measures of this test.
Methods: We developed a new speech comprehension test using audio-visual recordings of spontaneous conversations between two talkers. We applied a category monitoring paradigm in which listeners were given a word category and responded to target words related to the given category by pressing a hand-held button. The conversations were combined with babble noise at three different signal-to-noise ratios (SNRs) to vary the task difficulty. The outcome measures were listening effort self-rating, hit rate, response time (RT), and head/gaze switch delay. We tested thirty participants with normal hearing who spoke English as their first language. We examined the individual outcome measures in the three SNR conditions and correlated them with listening effort self-ratings.
Results: With increasing listening difficulty, listening effort ratings increased, hit rate decreased, RT increased, and head switch delay decreased. There was no visible effect of SNR on the gaze switch delay. The effort ratings showed a significant negative correlation with hit rate, a significant positive correlation with RT, and a significant negative correlation with head switch delay.
Conclusion: The proposed test provides a sensitive assessment of listeners’ speech comprehension performance in the real world, even though the outcome measures are limited by various participant- and material-related factors. Hit rate, RT, and head switch delay may be potential indicators of listening effort. The current study may provide normative data for future studies.
