Dissertations and Theses @ UNI

Availability

Open Access Thesis

Keywords

Audiometry; Sounds;

Abstract

The warble tone, as an auditory stimulus, is apparently being used in a number of clinical settings. However, it is being used without knowledge of possible threshold differences which may exist between it and the pure tone stimulus. Recent studies comparing the two stimuli have been limited to extremely small samples and to only trained listeners. Also, they provide mostly theoretical information based on the effect of various warble parameters on warble tone thresholds. The purpose of the present study was to compare obtained pure tone and warble tone thresholds for a large group of normal-hearing inexperienced listeners while using a warble tone stimulus presently available on a clinical audiometer. One hundred ninety eight normal-hearing inexperienced listeners were each administered pure tone and warble tone threshold tests for six frequencies at octave intervals from 250 through 8000 Hz. The warble tone stimulus utilized was provided by the Maico MA-24 audiometer and consisted of an approximate ±5% frequency deviation with a modulation rate of 5 per second. The data for each test frequency were subjected to a single factor analysis of variance for repeated measures. Results of the analysis of variance procedure for the test frequencies 250 and 1000 Hz indicate that the mean threshold differences for these frequencies are not statistically significant (p>.05, F = 0.122; and p> .05, F = 0.726 respectively). However, statistically significant differences were found for the test frequencies 500 Hz (p< .01, F = 8.920), 2000 Hz (p< .01, F = 10.675), 4000 Hz (p< .01, F = 25.568), and 8000 Hz (p< .01, F = 76.880). Although statistically significant differences were found at four of the six test frequencies, the mean differences for all frequencies were quite small with the largest being 2.298 dB at 8000 Hz. It appears that clinically significant differences (±5 dB) between pure tone and warble tone thresholds would not be found with the possible exception of 8000 Hz. At this frequency the mean difference combined with the large amount of threshold variability might result in a number of 5 dB shifts. Standard deviations tended to increase proportionately, for warble tone and pure tone thresholds, as the frequency increased. However, the warble tone consistently displayed less threshold variability than the pure tone stimulus. The point to be made is that both stimuli followed the same trend. In general, it appears that warble tone stimulus parameters up to and including frequency deviations of ±5% with modulation rates of 5 per second will not result in threshold differences which would alter the interpretation of the audiogram.

Year of Submission

1973

Degree Name

Master of Arts

Department

Department of Speech Pathology and Audiology

First Advisor

Dale Robinson

Second Advisor

Verner Jensen

Third Advisor

James House

Comments

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Date Original

1973

Object Description

1 PDF file (92 leaves)

Language

en

File Format

application/pdf

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