Effects of vocoding and intelligibility on the cerebral response to speech

Strelnikov, K., Massida, Z., Rouger, J., Belin, P. and Barone, P. (2011) Effects of vocoding and intelligibility on the cerebral response to speech. BMC Neuroscience, 12(1), p. 122. (doi: 10.1186/1471-2202-12-122) (PMID:22129366) (PMCID:PMC3247873)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1186/1471-2202-12-122

Abstract

<p><b>Background:</b> Degrading speech through an electronic synthesis technique called vocoding has been shown to affect cerebral processing of speech in several cortical areas. However, it is not clear whether the effects of speech degradation by vocoding are related to acoustical degradation or by the associated loss in intelligibility. Using vocoding and a parametric variation of the number of frequency bands used for the encoding, we investigated the effects of the degradation of auditory spectral content on cerebral processing of intelligible speech (words), unintelligible speech (words in a foreign language), and complex environmental sounds.</p> <p><b>Results:</b> Vocoding was found to decrease activity to a comparable degree for intelligible and unintelligible speech in most of the temporal lobe. Only the bilateral posterior temporal areas showed a significant interaction between vocoding and intelligibility, with a stronger vocoding-induced decrease in activity for intelligible speech. Comparisons to responses elicited by environmental sounds showed that portions of the temporal voice areas (TVA) retained their greater responses to voice even under adverse listening conditions. The recruitment of specific networks in temporal regions during exposure to degraded speech follows a radial and anterior-posterior topography compared to the networks recruited by exposure to speech that is not degraded.</p> <p><b>Conclusions:</b> Different brain networks are involved in vocoded sound processing of intelligible speech, unintelligible speech, and non-vocal sounds. The greatest differences are between speech and environmental sounds, which could be related to the distinctive temporal structure of speech sounds.</p>

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Rouger, Dr Julien and Belin, Professor Pascal
Authors: Strelnikov, K., Massida, Z., Rouger, J., Belin, P., and Barone, P.
College/School:College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
Journal Name:BMC Neuroscience
ISSN:1471-2202

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
429751The perception of voice gender and identity - a combined behavioural, electrophysiological and neuroimaging approachPascal BelinBiotechnology and Biological Sciences Research Council (BBSRC)BB/E003958/1Cognitive Neuroimaging & Neuroengineering Technologies