Investigating Cortical Responses to Noise-Vocoded Speech in Children with Normal Hearing Using Functional Near-Infrared Spectroscopy (fNIRS)

Mushtaq, Faizah; Wiggins, Ian M.; Kitterick, Pádraig T.; Anderson, Carly A.; Hartley, Douglas E.H.

Abstract

Whilst functional neuroimaging has been used to investigate cortical processing of degraded speech in adults, much less is known about how these signals are processed in children. An enhanced understanding of cortical correlates of poor speech perception in children would be highly valuable to oral communication applications, including hearing devices. We utilised vocoded speech stimuli to investigate brain responses to degraded speech in 29 normally hearing children aged 6–12years. Intelligibility of the speech stimuli was altered in two ways by (i) reducing the number of spectral channels and (ii) reducing the amplitude modulation depth of the signal. A total of five different noise-vocoded conditions (with zero, partial or high intelligibility) were presented in an event-related format whilst participants underwent functional near-infrared spectroscopy (fNIRS) neuroimaging. Participants completed a word recognition task during imaging, as well as a separate behavioural speech perception assessment. fNIRS recordings revealed statistically significant sensitivity to stimulus intelligibility across several brain regions. More intelligible stimuli elicited stronger responses in temporal regions, predominantly within the left hemisphere, while right inferior parietal regions showed an opposite, negative relationship. Although there was some evidence that partially intelligible stimuli elicited the strongest responses in the left inferior frontal cortex, a region previous studies have suggested is associated with effortful listening in adults, this effect did not reach statistical significance. These results further our understanding of cortical mechanisms underlying successful speech perception in children. Furthermore, fNIRS holds promise as a clinical technique to help assess speech intelligibility in paediatric populations.

Citation

Mushtaq, F., Wiggins, I. M., Kitterick, P. T., Anderson, C. A., & Hartley, D. E. (2021). Investigating Cortical Responses to Noise-Vocoded Speech in Children with Normal Hearing Using Functional Near-Infrared Spectroscopy (fNIRS). Journal of the Association for Research in Otolaryngology, 22(6), 703-717. https://doi.org/10.1007/s10162-021-00817-z

• Journal Article Type: Article
• Acceptance Date: Sep 7, 2021
• Online Publication Date: Sep 28, 2021
• Publication Date: Dec 1, 2021
• Deposit Date: Sep 22, 2021
• Publicly Available Date: Sep 29, 2022
• Journal: JARO - Journal of the Association for Research in Otolaryngology
• Print ISSN: 1525-3961
• Electronic ISSN: 1438-7573
• Publisher: Springer Science and Business Media LLC
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Issue: 6
• Pages: 703-717
• DOI: https://doi.org/10.1007/s10162-021-00817-z
• Keywords: Sensory Systems; Otorhinolaryngology
• Public URL: https://nottingham-repository.worktribe.com/output/6295856
• Publisher URL: https://link.springer.com/article/10.1007%2Fs10162-021-00817-z