Modulation masking release reduction as a function of time-compressed speech

Fernando Augusto Pacífico,Karina Paes Advincula,Maria Lucia Gurgel Da Costa,Ana Augusta De Andrade Cordeiro,Silvana Maria Sobral Griz,Denise Costa Menezes

doi:10.1590/1982-0216/20202257720

Fernando Augusto Pacífico, Karina Paes Advincula + Show 4 more

Open Access

https://doi.org/10.1590/1982-0216/20202257720

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Journal: Revista CEFAC	Publication Date: Jan 1, 2020
License type: CC BY 4.0

Affiliation: Universidade Federal de Pernambuco

Abstract

ABSTRACT Purpose: to investigate the magnitude of the modulation masking release in sentence recognition as a function of compression level and modulation rate. Methods: sentences of the Brazilian Portuguese version of the Hearing in Noise Test sentences were used as stimulus. The sentence recognition thresholds were established as a function of speech compression level (0%, 33%, and 50%) in steady and modulated noise at different modulation rates (4, 10, 32 Hz). The analysis of variance was performed for repeated measures, using the 5% significance level. Results: sentence recognition thresholds were higher for higher compression levels in the different types of noise. However, thresholds were smaller for modulated noises. Also, the magnitude of modulation masking release decreased as speech compression level increased. Nevertheless, no difference was observed in compressed speech between different noise modulation rates, in relation to the speech compression level. Conclusion: the magnitude of the modulation masking release decreased as the speech time-compression increased. Also, the reductions in modulation masking release, in relation to the speech time-compression level, did not differ between the masking-noise modulation rates (4, 10, and 32 Hz).

Highlights

In the last decades, many studies have compared speech recognition in steady noise with speech recognition in modulated noise, both presented with the same speech-to-noise ratio (SNR)[1,2,3]
The listener’s auditory system can temporarily process the masking-noise envelope, with periods when the SNR is less favorable and periods when SNR is more favorable
The modulation masking release (MMR) depends in part on the fidelity in which the masking-noise envelope is decoded by the auditory system[1]

Summary

Introduction

Many studies have compared speech recognition in steady noise with speech recognition in modulated noise, both presented with the same speech-to-noise ratio (SNR)[1,2,3]. The MMR can be explained when the intensity levels of the modulated noise are reduced (moments of minimal intensity), providing a listener brief glimpses of speech information to a more favorable SNR4,5. The listener’s auditory system can temporarily process the masking-noise envelope, with periods when the SNR is less favorable (when noise is modulated in its maximal intensity) and periods when SNR is more favorable (when noise is modulated in its minimal intensity). Several factors related to masking noise and speech material can change MMR magnitude, such as intensity, interruption rate, cyclic ratio, and modulation depth[6]. Greater MMR magnitudes for slower modulation rates (at around 10 Hz or lower) have been reported[2,5,7]

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Results

Conclusion