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).
Keywords:
Perceptual Masking; Speech Perception; Acoustic Stimulation; Acoustics; Hearing
Thumbnail
Captions: Mean of the thresholds of recognition in stable (full red circle) and modulated noise at 4 Hz (empty red circle). Mean of the thresholds of recognition in stable (full blue square) and modulated noise at 10 Hz (empty blue square). Mean of the thresholds of recognition in stable (full green triangle) and modulated noise at 32 Hz (empty green triangle). Error bars of 1 SD.