title: Perceptual consequences of changes in vocoded speech parameters in various reverberation conditions.
abstract: 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.
authors.affiliation: Adam Mickiewicz University, Poznan, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Drgas
authors.forename: Magdalena A
authors.initials: MA
authors.lastname: Blaszak
mesh_terms: 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