Document Detail


Benefit of high-rate envelope cues in vocoder processing: effect of number of channels and spectral region.
MedLine Citation:
PMID:  19062865     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In cochlear implants, or vocoder simulations of cochlear implants, the transmission of envelope cues at high rates (related to voice fundamental frequency, f0) may be limited by the widths of the filters used to form the channels and/or by the cutoff frequency, f(lp), of the low-pass filters used for envelope extraction. The effect of varying f(lp) in tone and noise vocoders was investigated for channel numbers, N, from 6 to 18. As N increased, the widths of the channels decreased. The value of f(lp) was 45 Hz (envelope or "E" filter), or 180 Hz (pitch or "P" filter). The following combinations of cutoff frequencies were used for channels below and above 1500 Hz, respectively: EE, PE, EP, and PP. Results from a competing-talker task showed that the tone vocoder led to better intelligibility than the noise vocoder. The PP condition led to the best intelligibility and the EE condition to the worst. For N=6, intelligibility was better for condition PE than for condition EP. For N=18, the reverse was true. The results indicate that the channel bandwidths can compromise the transmission of f0-related envelope information, and suggest that vocoder simulations of cochlear-implant processing have limitations.
Authors:
Michael A Stone; Christian Füllgrabe; Brian C J Moore
Related Documents :
3974985 - Use of a short wavelength filter in an operating microscope.
24312285 - Strategies for expanding the operational range of channelrhodopsin in optogenetic vision.
23686185 - A pilot study of the eeg patterns of subjects with corrected vision - biomed 2013.
2721825 - Analysis of auditory evoked potentials by magnitude-squared coherence.
24149225 - Underwater stroke kinematics during breathing and breath-holding front crawl swimming.
8817555 - Violation of superposition by the vestibulo-ocular reflex of the goldfish.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of the Acoustical Society of America     Volume:  124     ISSN:  1520-8524     ISO Abbreviation:  J. Acoust. Soc. Am.     Publication Date:  2008 Oct 
Date Detail:
Created Date:  2008-12-09     Completed Date:  2009-03-05     Revised Date:  2014-02-19    
Medline Journal Info:
Nlm Unique ID:  7503051     Medline TA:  J Acoust Soc Am     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2272-82     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acoustic Stimulation
Adult
Audiometry, Speech
Auditory Threshold
Cochlear Implants*
Computer Simulation*
Cues*
Female
Humans
Male
Noise
Perceptual Masking*
Prosthesis Design
Reproducibility of Results
Signal Processing, Computer-Assisted*
Speech Acoustics
Speech Intelligibility*
Young Adult
Grant Support
ID/Acronym/Agency:
G8717539//Medical Research Council

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Perception of rhythmic grouping depends on auditory experience.
Next Document:  Analysis of facial motion patterns during speech using a matrix factorization algorithm.