Perceptual consequences of changes in vocoded speech parameters in various reverberation conditions.
OBJECTIVE
To study the perceptual consequences of changes in parameters of vocoded speech in various reverberation conditions.


METHODS
The 3 controlled variables were number of vocoder bands, instantaneous frequency change rate, and reverberation conditions. The effects were quantified in terms of (a) nonsense words' recognition scores for young normal-hearing listeners, (b) ease of listening based on the time of response (response delay), and (c) the subjective measure of difficulty (10-degree scale).


RESULTS
It has been shown that the fine structure of a signal is a relevant cue in speech perception in reverberation conditions. The results obtained for different number of bands, frequency-modulation cutoff frequencies, and reverberation conditions have shown that all these parameters are important for speech perception in reverberation.


CONCLUSIONS
Only slow variations in the instantaneous frequency (<50 Hz) seem to play a critical role in speech intelligibility in anechoic conditions. In reverberant enclosures, however, fast fluctuations of instantaneous frequency are also significant.
Drgas
Szymon
S
Adam Mickiewicz University, Poznan, Poland.
Blaszak
Magdalena A
MA
D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D006801:Humans; D011571:Psychoacoustics; D011930:Reaction Time; D013060:Speech; D013061:Speech Acoustics; D013067:Speech Perception; D055815:Young Adult