Table Of Content\ Z. 13 C
PURDUE UNIVERSITY
THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION
Gayland L. Drae^ert________________________________
by
RELATIONSHIPS BBTWKËN VOICK VARIABLES
entitled
AND SPEECH INTELLIGIBILITY IN HICjH LEVEL NOISE
COMPLIES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES
AND IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS
FOR THE DEGREE OF
Doctor of Philosophy______________________________
Professor in Charge of Thesis
Hear of School or Department
August________ ie50 _
TO THE LIBRARIAN:-----
49-
THIS THESIS IS NOT TO BE REGARDED AS CONFIDENTIAL.
PKOFESSOB rsr OHAHGB
GJÏAD. SCHOOL F OHM O—3.40—1M
RELATIONSHIPS BETWEEN VOICE VARIABLES
AND SPEECH INTELLIGIBILITY IN HIGH LEVEL NOISE
A Thesis
Submitted to the Faculty
of
Purdue University
by
Gayland L* Draegert
In partial Fulfillment of the
Requirements for the Degree
of
Doctor of Philosophy
August, 1950
ProQuest Number: 27714165
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ACKNOWLEDGMENTS
This investigation was undertaken at the Voice Science
Laboratory, Purdue University, in conjunction with the office
of Naval Research, Contract N6ori-104, Project 20-K-l.
The Purdue Research Foundation sponsored the local project
under the designation PRF #339. The author is indebted
to all the members of the project staff for their assis
tance in the conduct of the investigation. Of especial
aid in planning and conducting the experiment was Dr. M. D.
Steer, Director of PRF #339. Valuable criticisms were
also contributed by Dr. Alan H. Monroe, Dr. T. D. Hanley,
and Dr. L. M. Baker. Dr. Irving W. Burr has given fre
quent counsel regarding statistical procedures. In addi
tion to those specifically named the author is indebted
to colleagues in the department who assisted in obtaining
experimental subjects.
VITA
Gayland L. Draegert
Born October 7, 1914
Education
Graduated from Academy, Western Illinois State
College, Macomb, Illinois, June, 1931.
B. Ed. Degree from Western Illinois State College,
Macomb, Illinois, June, 1934.
M. A. Degree from State University of Iowa, Iowa
City, Iowa, August, 1937.
Experience
Instructor in Speech and English, Normandy High
School, St. Louis, Missouri, one year, 1937-1938.
Instructor in Speech and Technical Director of
Theatre, Duquesne University, Pittsburgh, Penn
sylvania, two years, 1938-1940.
Instructor in English, Colona High School, Colona,
Illinois, one semester, 1942.
Instructor in Speech, Radio, and Voice Communications
for US Army Air Force, two years, 1942-1944, stationed
at Sioux Falls Army Air Field and St. Louis University
Research Associate In Voice Communications for Psycho
logical Corporation, one year, 1944-1945, Waco Voice
Communication Laboratory, Waco, Texas.
Instructor in Speech, Ohio University, Athens, Ohio
one year, 1945-1946.
Instructor in Speech and PRF Fellow, Purdue University
Lafayette, Indiana, four years, 1946-1950.
Publications
Intelligibility Related to Articulation, Speech Mono
graphs, Vol. 13, No. 2, 1946.
The Purdue Pitch Meter — A Direct-Reading Fundamental
Frequency Analyzer, with Dempsey, M. E., Siskind, R* P
and Steer, M. D., Journal of Speech and Hearing Dis
orders, June, 1950.
TABLE OF CONTENTS
ABSTRACT----------------------------------------------- i
INTRODUCTION------- 1
PURPOSE AND SCOPE OF INVESTIGATION---------------------5
HISTORY OF THE PROBLEM---------------------------------- 7
Intelligibility Testing-------------------- --7
Voice Variables in Noise— — ---------- ------— -— 12
Loudness- — ------------------------ 12
Time— — — — — — — — — — — ----------------is
Pitch--------------------------------------------- 20
Quality----------- — 23
Articulation— — ------- 23
EXPERIMENTAL SUBJECTS--------------------------------- 26
PROCEDURE WITH SUBJECTS------------------------------- 28
METHODS FOR MEASUREMENTS------------------------------ 34
Interphone Trainer-------------------------- -34
Speaker Rating---------- — ---36
Speaker Intelligibility-----------------------------36
Recording---— ------------ 37
Intensity---- ---- — ---- 40
Time--- — ------------— --------------------- ---40
Quality------ 43
PitEh----------------------------------------- 43
Voice Control------------- -44
Vital Capacity — ------------------------------ 45
RESULTS----------------- 46
CONCLUSIONS AND DISCUSSION--------------------------- 65
APPENDIX ------------------------------------------- 68
Appendix I — Speaker Rating Sheet --------------68
Appendix II Sample Exercise Blank----- ------- --70
Appendix III -- Answer Forms- -----------------72
Appendix IV — Speaker Word Lists— ------------ 85
Appendix V -- Prose Passage-------- 89
Appendix VI — Procedure for Recording onD iscs 90
Appendix VII -- Procedure Used for Playing
Recorded Tape ------91
BIBLI0GRAPHY----------------------- '-----------92
LIST OF FIGURES AND TABLES
Figure Page
1. Schematic diagram of arrangement of subjects
and equipment employed in experimental
intelligibility measurements---------- ----- ----— 29
2. Simplified functional block diagram of port
able interphone trainer. Device 8-1, arranged
for testing--— ----- 35
3. Major components in initial recording system— ----39
4. Schematic diagram of method used to obtain
speech signal from carbon microphone
line for recording------------------ 39
5. Equipment arranged for copying from disc
to tape---------- — — — -39
6. Equipment arranged for intensity measurements— ----41
7* Equipment arrangement for speech sound time
measurements— — — — ---- --41
8. Intelligibility scores from recorded lists
for selected population---------------------- --47
9. Intelligibility scores for unselected
population--------- -----------------------------— 49
10. Speaker ratings for unselected population----------49
11. Mean syllable duration for two types of
reading material----------------------------------- 51
12. Mean syllable intensity for two types of
reading material----------------- 52
13. Intensity variability for two types of
reading material----------------------------------- 52
14. Mean fundamental frequency for word lists---------- 54
15. Voice quality indicated by low frequency
intensity minus high frequency intensity
using 800 cps division point — --------------------54
16. Reading rate for prose--------- -56
17. Proportion of speech time for prose reading— --- 56
18. Voice control — ability to sustain phonation— --— 58
19. Vital capacity in liters--------------------------- 58
Table
1. Coefficients of correlation between measures------- 59
2. Means and standard deviations for intelli
gibility test and voice variables for 88
speakers----------------- 62
3a. Comparison between speakers of superior
and inferior intelligibility reading test
word lists --- 63
3b. Comparison between speakers of superior and
inferior intelligibility reading a prose
passage-- — --------------- 64
