Slide Slam C16 Sandbox Series
Relationship between persistence and speech intelligibility of time-compressed speech
Susan Teubner-Rhodes1, Rebecca Dunterman1, Sridhar Krishnamurti1, Anna Hill1; 1Auburn University
Older adults report greater listening effort than younger adults, especially for degraded speech . Individuals facing effortful listening during time-compressed (i.e., rapid) speech may resort to persistence, the ability to exert effort to overcome difficulty , as a top-down processing strategy. Indeed, persistence predicts neural activity in the dorsal anterior cingulate cortex that detects and overcomes errors when recognizing speech in background noise . Pupil dilation is an objective measure that can track the listening effort associated with speech intelligibility for young, middle-aged, and older adults [3-4]. Because the pupil response reflects cortical inputs to the autonomic nervous system, increases in pupil dilation indirectly measure the attention system’s response to increasing task demands . The present study examines how persistence affects accuracy and pupil dilation (i.e., listening effort) during recognition of time-compressed speech in healthy younger and older adults. We report results from 11 younger adults aged 18-35 years, as data collection for older adults was paused due to Covid-19. Participants completed background questionnaires to obtain demographic information and were screened for mild cognitive impairment. They completed verbal working memory and processing speed assessments, and the Wisconsin Card Sorting Task-64  to assess individual differences in shifting and persistence. Participants underwent a vision screening and a standard audiological assessment. Then, they completed a speech recognition task. On each of 36 trials, participants listened to and repeated 4 words presented at time-compression rates of 0% (normal speech), 30% (rapid speech), and 60% (very rapid speech). Pupil diameter was measured during listening using Micromedical Video Nystagmography goggles, in an illumination-controlled environment. Analyses examined the peak pupil diameter in 1-second increments from speech onset. Recognition accuracy was 8% higher for 0%-compressed versus 30%-compressed words (t(10) = 4.98, p < .01) and 5% higher for 30%-compressed versus 60%-compressed words (t(10) = 3.07, p = .01). Compression significantly affected pupil dilation (F(1.03, 8.22) = 6.86, p = .03) and this effect interacted significantly with persistence (F(1.03, 8.22) = 8.18, p = .02) and time window (F(1.44, 11.50) = 5.47, p = .03). In individuals with higher persistence, pupil dilation increased linearly from 0% to 30% to 60% compression, with peak dilation occurring 2-3 seconds after trial onset. In contrast, individuals with lower persistence exhibited maximal pupil dilation in the 30% condition, peaking 4-5 seconds after trial onset. Results suggest that, even among healthy young adults, persistence affects the extent to which individuals continue to exert effort as speech rate increases. Those with lower persistence exhibit a drop-off in a physiological index of listening effort as speech rate rises, suggesting that these individuals may be vulnerable to speech comprehension deficits.  Anderson Gosselin & Gangé. J Speech Lang Hear Res. 2011;54:944-58.  Teubner-Rhodes et al. Neuropsychologia. 2017;102:95-108.  Kuchinsky SE et al. Psychophysiology. 2013;50(1):23-34.  Wingfield A. Ear Hear. 2016;Suppl1:35S-43S.  Zekveld et al. Ear Hear. 2010;31:480-90.  Kongs et al. Wisconsin Card Sorting Test—64 card version. Lutz (FL): PAR Inc.; 2000.