The purpose of this study was to test the possible influence of perceptual set on listeners' judgments of voice quality deviations. Perceptual set was created by instructions given to an experimental group which limited their choices, thus encouraging a particular response. The effect of set on the overall performance of the group, on backward versus forward voice samples and on the level of experience of the listener were all investigated.

The sample for this study was comprised of 24 students of speech pathology and audiology. The subjects were divided into matched experimental and control groups and asked to listen to a prepared tape containing 27 voice samples presented forward and 27 voice samples presented backward. The experimental group was given instructions to judge the voice samples simply for the presence of or the absence of nasality. The control group was asked to judge the samples for a variety of voice quality disorders. The scores from each group were computed and a statistical analysis was used to determine what effect perceptual set had on the experimental group.

The results of this study indicate that perceptual set does not play a significant role in influencing listener judgments of voice quality disorders, at least in inexperienced listeners. Further, perceptual set is not a factor in backward versus forward performance in inexperienced listeners, nor does it influence the listeners at one level more than those at another level for any of the three levels of experience of the group tested.

The results of this study indicate that perceptual set created by specific instructions does not influence the evaluation of voice quality disorders at least by inexperienced listeners. Speech pathologists who deal with the evaluation and treatment of voice quality disorders on a wide scale should be aware that this possibility exists, however, and take steps to avoid it in their personal experience.

LLU Discipline

Speech Pathology


Communicative Disorders


Graduate School

First Advisor

Jean Lowry

Second Advisor

Jack Hartley

Third Advisor

Maurice Hodgen

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Speech Disorders; Perceptual Disorders

Subject - Local

Loma Linda University. Speech-Language Pathology program -- dissertations.



Page Count

v; 52

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives