Sponsor
Portland State University. Department of Speech Communication
First Advisor
James F. Maurer
Date of Publication
2-1974
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Speech: Emphasis in Speech Pathology/Audiology
Department
Speech and Hearing Sciences
Language
English
Subjects
Intelligibility of speech -- Testing, Hearing aids -- Evaluation
DOI
10.15760/etd.1965
Physical Description
1 online resource (ix, 51 pages)
Abstract
Hearing aid manufacturers commonly engineer automatic gain control (AGC) circuits which are aimed at reducing'sound tolerance problems and improving speech intelligibility among wearers. The most common type of AGC engineered is one utilizing a fast attack time. The present study was designed to evaluate the effects of both fast and slow attack times on the intelligibility of speech. Twenty-four normal hearing subjects listened to sixty pre-recorded sentences through two types of hearing aid circuits. Thirty sentences were modified by a fast attack AGC circuit, and thirty sentences were modified by a slow attack AGC. The subjects marked one of four multiple~choice answers for each sentence.
The mean number of sentences answered incorrectly when heard through fast attack AGC was 8.25. When heard through slow attack AGC, the mean was 6.67. The performance differences which exist between these two modes of signal modification suggest that the fast attack does not improve intelligibility as significantly as slow attack time among normal listeners. Further investigation into the effects of slow attack AGC circuits on the user's ability to understand speech are recommended.
Rights
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Persistent Identifier
http://archives.pdx.edu/ds/psu/12552
Recommended Citation
Odell, Lee M., "Intelligibility of Speech Compared Through Two Limiter Compression Circuits" (1974). Dissertations and Theses. Paper 1966.
https://doi.org/10.15760/etd.1965