The pupil response reveals increased listening effort when it is difficult to focus attention.
Recent studies have shown that prior knowledge about where, when, and who is going to talk improves speech intelligibility. How related attentional processes affect cognitive processing load has not been investigated yet. In the current study, three experiments investigated how the pupil dilation response is affected by prior knowledge of target speech location, target speech onset, and who is going to talk. A total of 56 young adults with normal hearing participated. They had to reproduce a target sentence presented to one ear while ignoring a distracting sentence simultaneously presented to the other ear. The two sentences were independently masked by fluctuating noise. Target location (left or right ear), speech onset, and talker variability were manipulated in separate experiments by keeping these features either fixed during an entire block or randomized over trials. Pupil responses were recorded during listening and performance was scored after recall. The results showed an improvement in performance when the location of the target speech was fixed instead of randomized. Additionally, location uncertainty increased the pupil dilation response, which suggests that prior knowledge of location reduces cognitive load. Interestingly, the observed pupil responses for each condition were consistent with subjective reports of listening effort. We conclude that communicating in a dynamic environment like a cocktail party (where participants in competing conversations move unpredictably) requires substantial listening effort because of the demands placed on attentional processes.
Section Ear & Hearing, Department of Otolaryngology-Head and Neck Surgery and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: t.koelewijn@vumc.nl.
Thomas
T
Koelewijn
Section Ear & Hearing, Department of Otolaryngology-Head and Neck Surgery and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
Hilde
H
de Kluiver
Department of Biomedical Engineering, Center for Computational Neuroscience and Neural Technology, Boston University, Boston, USA.
Barbara G
BG
Shinn-Cunningham
Section Ear & Hearing, Department of Otolaryngology-Head and Neck Surgery and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Linnaeus Centre HEAD, Department of Behavioral Sciences and Learning, Linköping University, Linköping, Sweden.
Adriana A
AA
Zekveld
Section Ear & Hearing, Department of Otolaryngology-Head and Neck Surgery and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
Sophia E
SE
Kramer
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001288:Attention; D001302:Audiometry, Speech; D001767:Blinking; D003071:Cognition; D003463:Cues; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D015877:Miosis; D015878:Mydriasis; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D011680:Pupil / Q000502:physiology*; D012025:Reflex, Pupillary; D013017:Sound Localization; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors; D035501:Uncertainty; D055815:Young Adult