Relative contribution to speech intelligibility of different envelope modulation rates within the speech dynamic range

The contribution of envelope cues at different rates to intelligibility in a competing-speech task was measured as a function of the short-term envelope level. The target and background mixture was processed using tone vocoders. Envelope signals for each vocoder channel were simultaneously extracted...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of the Acoustical Society of America 2010-10, Vol.128 (4), p.2127-2137
Main Authors: Stone, Michael A., Füllgrabe, Christian, Moore, Brian C. J.
Format: Article
Language:English
Subjects:
Acoustic Stimulation
Adolescent
Adult
Audiometry
Auditory Pathways - physiology
Auditory Threshold
Biological and medical sciences
Channels
Cues
Envelopes
Female
Fundamental and applied biological sciences. Psychology
Humans
Intelligibility
Language
Male
Modulation
Noise levels
Perceptual Masking
Production and perception of spoken language
Psychology. Psychoanalysis. Psychiatry
Psychology. Psychophysiology
Sound Spectrography
Speech
Speech Acoustics
Speech Intelligibility
Thresholds
Time Factors
Vocoders
Young Adult
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The contribution of envelope cues at different rates to intelligibility in a competing-speech task was measured as a function of the short-term envelope level. The target and background mixture was processed using tone vocoders. Envelope signals for each vocoder channel were simultaneously extracted with two low-pass filters, the cutoff frequency of one filter (L) being two octaves below that of the other (H). The envelope from the H filter was used at the peaks and that from the L filter at valleys, or vice versa. This was achieved by cross-fading between the two envelope signals based on a "switching threshold" that was parametrically varied relative to the long-term RMS level of the channel signal. When the cutoff frequencies of the H and L filters were 50 and 12.5 Hz, changes in speech intelligibility occurred mainly when the switching threshold was between −18 and + 10   dB . The range was slightly narrower when the cutoff frequencies of the H and L filters were 200 and 50 Hz. Intensity-importance functions for higher-rate envelope modulations suggested that levels ranging from 20 dB below to about 10 dB above the channel RMS level were important, with maximum importance for levels around −5 dB.
ISSN:0001-4966
1520-8524
DOI:10.1121/1.3479546