Effects of vocoding and intelligibility on the cerebral response to speech.
BMC Neurosci
; 12: 122, 2011 Nov 30.
Article
en En
| MEDLINE
| ID: mdl-22129366
ABSTRACT
BACKGROUND:
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.RESULTS:
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.CONCLUSIONS:
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.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Acústica del Lenguaje
/
Inteligibilidad del Habla
/
Percepción del Habla
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Lóbulo Temporal
/
Red Nerviosa
Límite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
BMC Neurosci
Asunto de la revista:
NEUROLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Francia