The influence of harmonics on pure tone threshold measurements of subjects with moderately-severe to severe high frequency hearing impairments

Author

Laurence Abikoff

Date of Award

12-1983

Degree Type

Thesis

Degree Name

Master of Arts

Major

Audiology

Major Professor

David M. Lipscomb

Committee Members

Tomasz Letowski, Samuel Burchfield, Allan Diefendorf, Igor Nabelek

Abstract

Ten moderately-severe to- severely hearing impaired adult subjects were selected from The University of Tennessee Hearing and Speech Center client population to participate in a study designed to examine the effect of harmonic distortion level upon high frequency tonal thresholds.

Hearing thresholds were obtained at 4,000 Hz and 8,000 Hz for each subject using two presentation conditions: tones having a standard level of harmonic distortion as per the ANSI - 1969 protocol, and tones having a reduced level of harmonic distortion. The data obtained from a comparison of threshold results were statistically analyzed to determine if there were statistically significant differences in threshold sensitivity related to the level of harmonic distortion in the test stimuli. Subject thresholds were then determined for extra high frequency harmonics of the test tones. This procedure attempted to relate the lack of differences found in the primary test comparison to elevated hearing sensitivity for harmonics of the frequency under test.

Results of the t-test for related measures yielded no statistically significant difference between threshold levels for test tones with a standard level of harmonic distortion and test tones with a reduced level of harmonic distortion.

All subjects tested had markedly poorer threshold sensitivity for extra high frequencies than for the audiometric high frequency fundamentals. Therefore, no data could be obtained for a worst case example.

It was concluded that for a selected hearing impaired population reduction in the level of harmonic distortion does not appear to result in a significant change in threshold sensitivity for a high frequency fundamental tone under test.

Recommended Citation

Abikoff, Laurence, "The influence of harmonics on pure tone threshold measurements of subjects with moderately-severe to severe high frequency hearing impairments. " Master's Thesis, University of Tennessee, 1983.
https://trace.tennessee.edu/utk_gradthes/14746