Combining spectral and temporal modification techniques for speech intelligibility enhancement

Modifying clean speech prior to output in noisy conditions can lead to substantial intelligibility gains. Most algorithms operate by redistributing energy across the signal, leaving the timing of the underlying speech sounds intact. Other techniques do alter the timing of speech relative to the mask...

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Detalhes bibliográficos
Autores: Cooke, Martin, Aubanel, Vincent, García Lecumberri, María Luisa
Tipo de documento: artigo
Data de publicação:2019
País:España
Recursos:Universidad del País Vasco
Repositório:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/64011
Acesso em linha:http://hdl.handle.net/10810/64011
Access Level:Acceso aberto
Palavra-chave:speech modification
intelligibility
retiming
glimpsing
Descrição
Resumo:Modifying clean speech prior to output in noisy conditions can lead to substantial intelligibility gains. Most algorithms operate by redistributing energy across the signal, leaving the timing of the underlying speech sounds intact. Other techniques do alter the timing of speech relative to the masker. Both classes of approach – spectral and temporal – lead to a reduction in energetic masking. The current study examines how their combination affects intelligibility. Arguments can be made for both synergy and redundancy, and the presence of distortions introduced by both spectral and temporal approaches might even lead to an antagonistic combination. A cohort of native Spanish listeners identified keywords in sentences in unmodified form and following spectral, temporal and spectro-temporal modification, in the presence of a fluctuating masker. Errors in the spectro-temporal condition were substantially lower than following spectral or temporal modification alone, with a three-fold reduction compared to unmodified speech. Spectro-temporal gains were observed for all phonemes. A glimpse-based model of energetic masking incorporating speech rate changes predicts intelligibility (r =. 96), and a glimpsing analysis provides further insights into the distinct mechanisms through which spectral and temporal approaches lead to a release from energetic masking.