71t,17,Q58 WHITEHEAD, Robert Lowell, 1943- SOME SPECTROGRAPHIC AND PERCEPTUAL FEATURES OF NORMAL, VOCAL FRY, AND SIMULATED ABNORMALLY ROUGH VOWEL PHONATIONS. The University of Oklahoma, Ph.D., 1970 Speech Pathology University Microfilms, A XEROX Company, Ann Arbor, Michigan THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED THE UNIVERSITY OF OKLAHOMA GRADUATE COLLEGE SOfflE SPECTROGRAPHIC AND PERCEPTUAL FEATURES OF NORMAL, VOCAL FRY, AND SIMULATED ABNORMALLY ROUGH VOWEL PHONATIONS A DISSERTATION SUBMITTED TO THE GRADUATE FACULTY in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY BY Robert Lowell Whitehead Oklahoma City, Oklahoma 1970 SOIÏIE SPECTROGRAPHIC AND PERCEPTUAL FEATURES OF NORMAL, VOCAL FRY, AND SIMULATED ABNORMALLY ROUGH VDUJEL PHONATIONS APPROVED BY pO /y\A^ V . Y DISSERTATION COMMITTEE ACKNOWLEDGMENTS The author wishes to express his gratitude to Dr. Floyd W. Emanuel, director of this study, for his guidance, encouragement, and criticism throughout the planning and completion of the investigation. Appreciation is also expressed to the members of the dissertation com­ mittee, Dr. Donald T. Counihan, Dr. Walter L. Cullinan, Dr. Glenda 0. Ochsner, and Dr. Roy B. Deal, Or., for their helpful suggestions during the course of this study. Additional acknowledgment is made to Dr. Roy B. Deal, Or. and to Dr. Donald E. Parker, Department of Biostatistics and Epidemiology, University of Oklahoma Medical Center, for their assistance in the sta­ tistical analysis of the data. Thanks are due also to the individuals who participated in this study as subjects and judges. The author also wishes to express his gratitude to his wife, Beth, and to his parents, Mr. and Mrs. L. H. Whitehead, for their con­ stant encouragement, understanding, and support throughout this period of graduate study. This study was supported in part by an American Speech and Hearing Foundation Traineeship Award. Ill TABLE OF CONTENTS Page LIST OF T A B L E S ...................................................... vi LIST OF ILLUSTRATIONS ............................................... viii Chapter I. INTRODUCTION ............................................... 1 II. REVIEW OF THE LITERATURE.................................. 5 Perceptual Features of Vocal Fry and Vocal Roughness ..................................... 6 Acoustic Features of Vocal Fry and Vocal R o u g h n e s s ............................................. 11 Physiologic Features of Vocal Fry and Vocal R o u g h n e s s ............................................. 17 S u m m a r y .................................................. 21 III. DESIGN OF THE INVESTIGATION .............................. 23 Research Questions ....................................... 24 S u b j e c t s .................................................. 24 Speech Sample ........................................... 24 Instrumentation ......................................... 25 Description ........................................... 25 Signal System ....................................... 25 Audio Recording System .............................. 25 Wave Analyzing System .............................. 26 Playback System ..................................... 28 Fundamental Vocal Frequency Analyzing S y s t e m ............................................. 28 Calibration System .................................. 28 Calibration ........................................... 32 Audio Recording System .............................. 32 Wave Analyzing System .............................. 33 Procedures............................................... 33 R e c o r d i n g ............................................. 33 Spectral Analysis ..................................... 35 Fundamental Vocal Frequency Analysis ................. 37 Roughness Rating ....................................... 37 lïlode of Phonation R a t i n g .............................. 39 IV. RESULTS OF THE INVESTIGATION . ..................... 41 R e s u l t s ................................................. 41 Fundamental Vocal Frequency .......................... 41 Roughness Ratings ..................................... 46 iv TABLE OF CONTENTS— Continued Page Spectral Noise Levels ................................ 50 Spectral Noise Level and Roughness Rating Relationships ......................................... 57 D i s c u s s i o n ..................................................67 U. SUMMARY AND CONCLUSIONS....................................... 77 BIBLIOGRAPHY ........................................................ 82 APPENDIXES .............................................................89 A. Instructions to S u b j e c t s ..................................... 89 B. Instructions to J u d g e s ....................................... 92 C. Percentages of Inter- and Intra-Judge Roughness Rating Agreement ......................................... 96 D. The Number of Eleven Judges Concurring withthe Investigator's Identification of Normal, Vocal Fry, and Rough Samples of Five Vowels Produced by Twenty Subjects ............................. 98 E. Summary of Analyses of Variance and Duncan's New Multiple Range Tests .................................... 100 F. Details of Methods II and I I I ............................... 104 LIST OF TABLES Table Page 1. Fundamental Vocal Frequency for Each Normal, Vocal Fry, and Rough Vowel Produc t i o n ..................... - à2 2. Fundamental Vocal Frequency Means and Standard Deviations, and the Range of Fundamentals for Normal, Vocal Fry, and Simulated Abnormally Rough Vowels Produced by Twenty Adult Males ............... 45 3. Median Roughness Ratings for Each Normal, Vocal Fry, and Rough Vowel Production ............................ 47 4. Median Roughness Ratings for Normal, Vocal Fry, and Rough Productions of Each Vowel Averaged over Twenty S u b j e c t s ......................................... 49 5. Normal, Vocal Fry, and Rough Vowel Spectral Noise Level (SNL) Means and Standard Deviations for Twenty Male Subjects, and Differences between the Vocal Fry and Normal, Vocal Fry and Rough, and Rough and Normal Vowel SNL Means (SNLDs) ............. 54 6. Correlation Coefficients for Noise Levels Averaged over Spectral Segment 100 to 2600 Hz and Median Roughness Ratings for the Productions of Each Test V o w e l .................................................... 57 7. Correlation Coefficients for the Multiple Regression between Spectral Noise Levels in Each 100-Hz Spec­ tral Section from 100 to 2600 Hz and Median Rough­ ness Ratings for the Productions of Each Test Vowel .... 53 8. The Number of Residuals for Three Methods of Predic­ tion Greater than .50 and 1.0 Scale Value for Twenty Normal, Twenty Vocal Fry, and Twenty Simulated Ab­ normally Rough Productions of Each of Five V o w e l s ........... 65 9. Percentage of Inter-Dudge Roughness Rating Agreement ±1 Scale Value for Three Hundred Vowel Productions .... 97 10. Percentage of Intra-Oudge Roughness Rating Agreement ±1 Scale Value for Two Ratings of Fifty Vowel Productions ........................................... 97 11. The Number of Eleven Oudges Concurring with the In- , vestigator's Identification of Normal, Vocal Fry, and Rough Samples of Five Vowels Produced by Twenty Subjects ......................................... 99 VI LIST OF TABLES— Continued Table Page 12. Summary of an Analysis of Variance for the Fundamental Vocal Frequencies of Normal Vowels ........... 101 13. Duncan's New Multiple Range Test for Differences among Normal Vowel Fundamental Vocal Frequencies ........ 101 14. Summary of an Analysis of Variance for the Funda­ mental Vocal Frequencies of Vocal Fry V o w e l s .............. 102 15. Duncan's New Multiple Range Test for Differences among Vocal Fry Vowel Fundamental Vocal Fre­ quencies ..................................................... 102 15. Summary of an Analysis of Variance for the Funda­ mental Vocal Frequencies of Rough Vowels ................. 103 17. Duncan's New Multiple Range Test for Differences among Rough Vowel Fundamental Vocal Frequencies ..... 103 Ull LIST OF ILLUSTRATIONS Figure Page 1. Simplified Diagram of the Audio Recording System ............ 27 2. Simplified Diagram of the Ulaue Analyzing System ............ 29 3. Simplified Diagram of the Fundamental Vocal Fre­ quency Analyzing System ................................... 30 4. Simplified Diagram of the Calibration System ................ 31 5. (Top) Spectrum of a Normal /%/; (Bottom) Spectrum of a Vocal Fry /ae/ . ....................................... 51 5. (Top) Spectrum of a Rough /ae/; (Bottom) Spectrum of a Vocal Fry /ae/............................................52 7. Noise Levels in Each 100-Hz Spectral Section Aver­ aged over Twenty lYlale Subjects for Normal, Vocal Fry, and Simulated Abnormally Rough Productions of the Vowel /ae/.............................................. 56 8. Spectral Range 100 to 2600 Hz Noise Level Means and Median Roughness Ratings over Eleven Oudges for Twenty Male Subjects' Normal, Vocal Fry, and Simu­ lated Abnormally Rough Productions of the Vowel /u/ . 58 9. Spectral Range 100 to 2600 Hz Noise Level Means and Median Roughness Ratings over Eleven Oudges for Twenty Male Subjects' Normal, Vocal Fry, and Simu­ lated Abnormally Rough Productions of the Vowel /i/ . 59 10. Spectral Range 100 to 2600 Hz Noise Level Means and Median Roughness Ratings over Eleven Oudges for Twenty Male Subjects' Normal, Vocal Fry, and Simu­ lated Abnormally Rough Productions of the Vowel /a / .