Foundations of Modern Auditory Theory

456 Pages·1970·6.355 MB·English

by  Jerry Tobias (Eds.)

Foundations
of
Modern Auditory Theory
Edited by
Jerry V. Tobias
Federal Aviation Administration
Oklahoma City, Oklahoma
VOLUME I
1970
ACADEMIC PRESS New York San Francisco London
A Subsidiary of Harcourt Brace Jovanovich, Publishers
COPYRIGHT © 1970, BY ACADEMIC PRESS, INC.
ALL RIGHTS RESERVED.
NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM,
BY PHOTOSTAT, MICROFILM, RETRIEVAL SYSTEM, OR ANY
OTHER MEANS, WITHOUT WRITTEN PERMISSION FROM
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PRINTED IN THE UNITED STATES OF AMERICA
For
P. E. and W. K. R., among others
List of Contributors
Numbers in parentheses indicate the pages on which authors' contributions begin.
Georg von Békésy, Laboratory of Sensory Sciences, University of
Hawaii, Honolulu, Hawaii (305)
Donald N. Elliott, Department of Psychology, Wayne State University,
Detroit, Michigan (115)
Winifred (Riach) Fraser, Department of Psychology, Wayne State
University, Detroit, Michigan (115)
Lloyd A. Jeffress, Applied Research Laboratories and Department of
Psychology, University of Texas, Austin, Texas (85)
Jan O. Nordmark, Mathema AB, Stockholm, Sweden (55)
Bertram Scharf, Department of Psychology, Northeastern University,
Boston, Massachusetts (157)
Harold F. Schuknecht, Harvard Medical School and Massachusetts
Eye and Ear Infirmary, Boston, Massachusetts (381)
F. Blair Simmons, Division of Otolaryngology, Stanford University,
Stanford, California (343)
Arnold M. Small, Psychology and Speech Pathology and Audiology
Departments, University of Iowa, Iowa City, Iowa (1)
Donald C. Teas, Departments of Speech, Psychology, Physiology, and
Electrical Engineering, University of Florida, Gainesville, Florida
(255)
Juergen Tonndorf, Otolaryngology Department, College of Physi-
cians and Surgeons, Columbia University, New York (203)
W. Dixon Ward, Department of Otolaryngology, University of
Minnesota, Minneapolis, Minnesota (405)
xi
Preface
Once upon a time, a long time ago, there was a little girl who wanted
to learn about rabbits. She was a bright little girl so she went to the
library, where the librarian spent an hour searching out the very best
rabbit book available for a child of that age. It was well illustrated,
was written in clear, understandable terms, was filled with examples
of rabbit-life and rabbit wisdom, and was, all in all, a perfect choice
for the child.
A week passed and the little girl came back, carrying the book care-
fully to the woman who had given so much of her knowledge, her time,
and her energy to selecting the perfect book. When she had reshelved
it, the librarian asked, "How did you like it?" The little girl looked
very serious for a minute, and finally found just the right phrase. She
said, "It told me more about rabbits than I wanted to know."
For a long time now, I've been looking for a book that would tell
me more about ears than I wanted to know. It doesn't exist. This book
isn't it either, although it was devised for the purpose of filling more
gaps than any of the others do. It is for the same sort of reader whom
the long-lived standard references still attract.
When I first learned that there was nothing on my shelf to direct
me, with a minimum of pain, toward the answers to the commonest
questions about auditory function, structure, and response, I began a
campaign to get one or more of my colleagues to do a book. Every-
one refused. One experienced editor suggested that the easiest way
would be to write the thing myself, but since I didn't know much then
about being an editor, I didn't believe him. Now I can add my advice
to his: anyone who attempts to compile a treatise of the magnitude of
this one has to be an eccentric — if not when he starts, then certainly
by the time he's done.
Still, I learned that anyone with a strong, selfish, good reason for
continuing can do the editorial job. I had such a reason. This book
was written for my personal instruction and convenience. It puts at
my fingertips most of the kinds of information that I need when I'm
xiii
xiv PREFACE
working on a paper for a journal; it helps guide me through articles
that are only peripherally within my area of expertise; and it often is
adequate to warn me that my latest new insight is not really so new
or so clever. Not till now has it been possible to consult with so many
truly wise colleagues and to find such useful authoritative opinion on
the vagaries of critical bands or of periodicity pitch, or on any of
innumerable other topics, without spending too much time on atten-
uated literature searches or too much equipment money on long-
distance phone calls.
The greatest discovery of all was that nearly everyone in the field
had the same selfish interest that I did —they all wanted some handy
sourcebook for their desks, and since the only way to get one was to
compile one, I decided to edit, and the contributors decided to con-
tribute.
This is Volume I of the two-volume result. In it, most of the kinds of
information necessary to understand basic auditory processes is
brought together. The exposition is intended to be clear, but the style
is certainly not that of a primer. Readers ought to know enough about
hearing (though not necessarily about all of the subspecialties) to feel
competent to contribute a chapter themselves some day. The authors
wrote their chapters for each other, so any reader is, in some sense,
in the same category as a writer.
Some of the contents of this volume are a bit different from what one
might find in a book designed only as a text: several writers have
strong points of view and occasionally those biases are not popular.
But, as with many theoretically founded prejudices, startling and use-
ful conclusions sometimes result.
I have to offer one important apology to some readers. Several of
the classical areas in the field of audition have been left out. The
choice was mine and I accept the consequence. But such things as
loudness perception, to pick one example, are well treated in the texts
that, although 15 or 20 or 30 years old, are still available and are still
important. This book is not designed to fill gaps that don't exist. As a
result/it cannot successfully stand as the only sourcebook on your
desk, but I hope it can come close.
In acknowledging the people who did most to make this book hap-
pen, I have to start with the most important ones, the contributors —
von Békésy, Elliott, Fraser, Jeffress, Nordmark, Scharf, Schuknecht,
Simmons, Small, Teas, Tonndorf, and Ward. Then there's Earl
Schubert, who got me started in trying to figure out how auditory
systems do all the things that they do. Lloyd Jeffress deserves special
PREFACE XV
mention, too, for the continuing reminders he's given me and so
many others that good research can be a joy both to see and to do.
Among my own people, a few deserve special mention for having
turned a bibliographical holocaust into an orderly and correct refer-
encing system. They checked every citation, proofread every refer-
ence, checked each article and book mentioned in any chapter against
the original source material, arranged everything according to the
British Museum's standard (the most universally acceptable for so
wide a range of scientific writing), and finally rechecked it all after the
type was set. They are Beth Burrus, Vic Jackson, Phyllis Ketchum, Pat
Layard, Linda Osterhaus, Douglas Polk, and Jan Vorse.
Chapter One
Periodicity Pitch
FOREWORD
Not long ago, auditory theory was only pitch theory. The critical questions being
asked about the auditory system pertained to such things as whether the all-or-none
principle of neural conduction meant that there could be no "telephone" transmission,
whether the existence of diplacusis could be reconciled with the volley theory, or
whether evidence of phase perception was too much for the place theory to account for.
Some of these kinds of questions still arise, but the theories to which the issues are
now taken are compound, eclectic statements that allow parts of the auditory process
to be handled by a place mechanism in the end organ, part by a volleying neural net-
work, part by mechanical and electrical inhibitory processes, and so on. Among the
areas that still seem mysterious is periodicity pitch. The basic problem arises from data
that show listeners are able to perceive modulation frequencies when energy at those
frequencies is carefully kept out of the stimulus. The resolution of the periodicity pitch
question leads necessarily to a resolution of the classic theoretical problems of audition.
Is the phenomenon one based on demodulation by the ear? If so, then the analysis of an
envelope frequency is identical to the analysis of any other similar frequency. If not,
then what is the mechanism by which "nonexistent" tones are heard? Arnold Small has
addressed himself to such questions for most of his research career.
1
Periodicity Pitch
Arnold M. Small*
I. HISTORICAL ANTECEDENTS
Many of the phenomena reviewed in this chapter are not new. Their
basis —indeed, in some cases, their existence —has been debated and
has stimulated research for well over 200 years. Often, there is a
tendency to discount older research simply because of its age. For ex-
ample, older work in hearing is discounted for its imprecision of
stimulus specification. However, in the area of pitch perception, the
limitations of older equipment may not be serious and become less so
when only relative pitch or changes in pitch are considered. In this
light, it is instructive to review some older data and their interpreta-
tion.
Although periodicity pitch has gone by many names throughout the
years, it may be defined by a particular stimulus configuration coupled
with a specific listener response. Thus, periodicity pitch, operation-
ally, is the pitch assigned to a complex stimulus and corresponding
approximately to the rate of signal envelope variation. Under these
circumstances, there is ordinarily little or no energy at the frequency
that corresponds to the perceived pitch. One might well ask what
class of signals fits this description.
In older research, several methods have been used to introduce
periodic variations into waveform envelopes. One is by interruptions
of a steady signal. König (1876), Dennert (1887), and Schaefer and
* Psychology and Speech Pathology and Audiology Departments, University of Iowa,
Iowa City, Iowa.
3
4 ARNOLD M. SMALL
Abraham (1901a, 1901b, 1902) were among the first to study stimuli of
this type. They all found a pitch that was equal to the rate of in-
terruption. For example, Schaefer and Abraham used a siren with four
holes followed by four blank spaces in a repetitive fashion around its
disc. They found two pitches: one was the same as would have been
produced if there had been all holes and no blanks, and the other
corresponded to the rate at which the groups of four open holes
appeared —three octaves lower.
A second way to generate envelope periodicities is by adding to-
gether two sinusoids whose frequencies are similar. The envelope
of such a combination undergoes amplitude changes at a rate equal
to the frequency difference between the sinusoids. With small fre-
quency separations, loudness changes, or beats, occur at the same rate
as the envelope amplitude changes. For larger separations and under
proper intensity conditions, a pitch is perceived —also corresponding
to the rate of envelope change. Such a pitch is called a beat note or
difference tone and, according to Jones (1935), was first reported by
Sorge, Romineu, and Tartini in 1744, 1751, and 1754, respectively.
Young (1800) and König (1876), expanding a suggestion originally
made by Smith (1749), proposed that the same envelope changes that,
when sufficiently slow, are heard as beats will, when sufficiendy rapid,
be perceived as difference tones. This hypothesis represents an early
attempt to relate pitch perception to the waveform of the stimulus.
These authors regarded any periodic change in the stimulus as a basis
for the perception of a tone. However, the precise nature and the
location of the central mechanism responsible for the interpretation
of waveform periodicity were never specified.
Helmholtz and his followers vigorously opposed this periodicity
point of view. Rather than accept the notion that the auditory system
may perceive pitch on the basis of waveform periodicity, they de-
fended a resonance theory wherein the ear performs a frequency
analysis. In his theory, Helmholtz (1863) provided an explicit physio-
logical basis for Ohm's (1843) acoustic law. Ohm's law, in essence,
states that the ear performs a Fourier analysis upon the stimulus; that
is, the sinusoidal components of a complex sound are individually
perceived. Curiously enough, Ohm formulated his statement largely
on the basis of some experiments by Seebeck (1841), and Seebeck,
as will be seen, disagreed vigorously with Ohm's law.
Helmholtz postulated a series of individual resonators consisting
of stretched transverse fibers on the basilar membrane. Each resonator