PERCEPTION OF THE MISSING FUNDAMENTAL IN PATIENTS WITH LOW FREQUENCY HEARING LOSS By GARY PAUL HORVATH B.Sc. (Hons.), The University of British Columbia, 1984 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Physiology) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October 1988 (c)Gary Paul Horvath, 1988 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Physiology The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date October 17, 1988 DE-6G/81) ABSTRACT The perception of the pitch of a harmonic complex tone missing its fundamental frequency was investigated in patients with unilateral sensorineural low-frequency hearing loss. Using a two-alternative forced choice adaptive method and an adjustment technique, patients matched the pitch of a complex tone consisting of the 3rd-7th or 3rd-10th harmonics, with a pure tone. Component frequencies were chosen such that they would fall within the intact portion of the patient's damaged ear, but whose fundamental frequency would fall within the damaged frequency area. Pitch matches were made monaurally and binaurally, with and without low-pass filtered noise. Results indicated that the patients tended to match the pitch of the lacking fundamentals to the complexes even though the frequency of the residue pitch fell within the range of elevated pure tone thresholds. It is concluded that information regarding the residue pitch is not mediated by cochlear nerve fibers with characteristic frequencies corresponding to the fundamental. Temporal cues carried by fibers with characteristic frequencies corresponding to the partials within the complex stimulus are most likely involved in pitch perception. Ii TARLE OF CONTENTS Abstract i i List of Abbreviations v List of Tables vi List of Figures viii Acknowledgements xi Introduction 1 Methods : 17 A. Subjects 17 B. Stimuli 18 C. Procedure 19 Pure Tone Audiogram 19 Pitch Training 20 Pitch Matching of Complex Tones Using a Two-Alternative Forced Choice Adaptive Method 21 Pitch Matching of Complex Tones Using an Up-Down Adjustment Technique 28 D. Statistical Analysis 30 Results 31 Pure Tone Audiograms 31 Pitch Matching of Complex Tones Using a Two-Alternative Forced Choice Adaptive Method....38 iii TABLE OF CONTENTS (CONT.1 i) Pitch Matching Control 99 ii) Pitch Matching Control with Noise 99 iii) Pitch Matching Between Ears 100 iv) Pitch Matching Between Ears with Noise 101 Pitch Matching of Complex Tones Using an Up-Down Adjustment Technique 102 i) Pitch Matching Control 102 ii) Pitch Matching Control with Noise 113 iii) Pitch Matching Between Ears 113 iv) Pitch Matching Between Ears with No ise 114 Discuss ion 123 Bibliography 140 iv LIST OF ABBREVIATIONS approx. approximation bel. below betw. between dB decibel, freq. frequency fund. fundamental har. harmonic HL hearing level Hz hertz kHz kilohertz mm millimeter msec millisecond MHz megahertz oct. octave P.M. pitch matching sec sec SEM standard error of the mean seq. sequence SL sensation level SPL sound pressure level start. starting w. with v T.TST DF' TABLES Table 1: Stepsizes of the Comparison Pure Tone (£2) 26 Table 2: Decrease in Threshold with Increasing Frequency for Each Patient... 36 Table 3: Selection of Components for the Complex Test Sound Used in the Pitch Matching Experiments 37 Table 4: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient A.D. Using the Two-Alternative Forced Choice Adaptive Routine 87 Table 5: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient A.F. Using the Two-Alternative Forced Choice Adaptive Routine 89 Table 6: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient G.F. Using the Two-Alternative Forced Choice Adaptive Routine 91 Table 7: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient L.F. Using the Two-Alternative Forced Choice Adaptive Routine 93 Table 8: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient R.L. Using the Two-Alternative Forced Choice Adaptive Routine 95 Table 9: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient J.W. Using the Two-Alternative Forced Choice Adaptive Routine 97 vi LIST OF TABLES (CONT.) Table 10: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient A.D. Using the Up-Down Adjustment Technique 103 Table 11: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient A.F. Using the Up-Down Adjustment Technique 105 Table 12: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient G.F. Using the Up-Down Adjustment Technique 107 Table 13: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient L.F. Using the Up-Down Adjustment Technique 109 Table 14: Pitch Values Assigned to the Pitch of the Complex Test Sound by Patient R.L. Using the Up-Down Adjustment Technique Ill Table 15: Summary of the Number of Matches to either the Fundamental and its Octaves, or to the Odd Harmonics and the Octaves below these Partials 116 Table 16: Summary of the Number o£ Matches to either the Missing Fundamental, or to the Presented Partials 120 vii T.TBT OF FIGURES Figure 1: Damaged and Intact Ear Audiograms of Patients A.D., A.F., and G.F 32 Figure 2: Damaged and Intact Ear Audiograms of Patients L.F., R.L., and J.W 34 Figure 3: Data from the Pitch Matching Control Procedure for Patient A.D. Using the Two-Alternative Forced Choice Adaptive Method 39 Figure 4: Data from the Pitch Matching Control with Noise Procedure for Patient A.D. Using the Two-Alternative Forced Choice Adaptive Method 41 Figure 5: Data from the Pitch Matching Between Ears Procedure for Patient A.D. Using the Two-Alternative Forced Choice Adaptive Method 43 Figure 6: Data from the Pitch Matching Between Ears with Noise Procedure for Patient A.D. Using the Two-Alternative Forced Choice Adaptive Method 45 Figure 7: Data from the Pitch Matching Control Procedure for Patient A.F. Using the Two-Alternative Forced Choice Adaptive Method 47 Figure 8: Data from the Pitch Matching Control with Noise Procedure for Patient A.F. Using the Two-Alternative Forced Choice Adaptive Method 49 Figure 9: Data from the Pitch Matching Between Ears Procedure for Patient A.F. Using the Two-Alternative Forced Choice Adaptive Method 51 Figure 10: Data from the Pitch Matching Between Ears with Noise Procedure for Patient A.F. Using the Two-Alternative Forced Choice Adaptive Method 53 viii LIST OF FIGURES (CONT.) Figure 11: Data from the Pitch Matching Control Procedure for Patient G.F. Using the Two-Alternative Forced Choice Adaptive Method 55 Figure 12: Data from the Pitch Matching Control with Noise Procedure for Patient G.F. Using the Two-Alternative Forced Choice Adaptive Method 57 Figure 13: Data from the Pitch Matching Between Ears Procedure for Patient G.F. Using the Two-Alternative Forced Choice Adaptive Method 59 Figure 14: Data from the Pitch Matching Between Ears with Noise Procedure for Patient G.F. Using the Two-Alternative Forced Choice Adaptive Method 61 Figure 15: Data from the Pitch Matching Control Procedure for Patient L.F. Using the Two-Alternative Forced Choice Adaptive Method 63 Figure 16: Data from the Pitch Matching Control with Noise Procedure for Patient L.F. Using the Two-Alternative Forced Choice Adaptive Method 65 Figure 17: Data from the Pitch Matching Between Ears Procedure for Patient L.F. Using the Two-Alternative Forced Choice Adaptive Method 67 Figure 18: Data from the Pitch Matching Between Ears with Noise Procedure for Patient L.F. Using the Two-Alternative Forced Choice Adaptive Method 69 Figure 19: Data from the Pitch Matching Control Procedure for Patient R.L. Using the Two-Alternative Forced Choice Adaptive Method 71 lx LIST OF FIGURES (CONT.) Figure 20: Data from the Pitch Matching Control with Noise Procedure for Patient R.L. Using the Two-Alternative Forced Choice Adaptive Method 73 Figure 21: Data from the Pitch Matching Between Ears Procedure for Patient R.L. Using the Two-Alternative Forced Choice Adaptive Method 75 Figure 22: Data from the Pitch Matching Between Ears with Noise Procedure for Patient R.L. Using the Two-Alternative Forced Choice Adaptive Method 77 Figure 23: Data from the Pitch Matching Control Procedure for Patient J.W. Using the Two-Alternative Forced Choice Adaptive Method ...79 Figure 24: Data from the Pitch Matching Control with Noise Procedure for Patient J.W. Using the Two-Alternative Forced Choice Adaptive Method 81 Figure 25: Data from the Pitch Matching Between Ears Procedure for Patient J.W. Using the Two-Alternative Forced Choice Adaptive Method 83 Figure 26: Data from the Pitch Matching Between Ears with Noise Procedure for Patient J.W. Using the Two-Alternative Forced Choice Adaptive Method 85 x ACKNOWLEDGEMENTS I would like to express my sincere gratitude to my supervisor, Dr. Dietrich Schwarz, for his encouragement and guidance throughout the duration of this project. I would also like to thank Ward Tomlinson and Joseph Li for their expert advice and help with instrumentation and computation.