Table Of ContentThe Acoustics
of Crime
The New Science of
Forensic Phonetics
APPLIED PSYCHOLINGUISTICS
AND COMMUNICATION DISORDERS
THE ACOUSTICS OF cruMrn
The New Science of Forensic Phonetics
Harry Hollien
APHASIA AND BRAIN ORGANIZATION
Ivar Reinvang
APPLIED PSYCHOLINGUISTICS AND MENTAL HEALTH
Edited by R. W. Rieber
COMMUNICATION DISORDERS
Edited by R. W. Rieber
PSYCHOLOGY OF LANGUAGE AND THOUGHT
Essays on the Theory and History of Psycholinguistics
Edited by R. W. Rieber
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The Acoustics
of Crime
The New Science of
Forensic Phonetics
Harry Hollien
University of Florida
Gainesville, Florida
Springer Science+B usiness Media, LLC
Library of Congress Cataloging-in-Publication Data
Hollien, Harry Francis, 1926-
The acoustics of crime : the new science of forensic phonetics /
Harry Ho 11ien.
p. cm. — (Applied psycho 1inguistics and communication
d i sorders )
Includes bibliographical references and index.
ISBN 978-1-4899-0675-5
1. Criminal investigation. 2. Phonetics. I. Title. II. Series.
HV8073.H624 199D
363.2'58~dc20 90-7448
CIP
ISBN 978-1-4899-0675-5 ISBN 978-1-4899-0673-1 (eBook)
DOI 10.1007/978-1-4899-0673-1
© Springer Science+Business Media New York 1990
Originally published by Plenum Press, New York in 1990
Softcover reprint of the hardcover 1st edition 1990
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
To Patti
My wife my colleague
my friend
Preface
There are many reasons for writing a book; this one was conceived and devel
oped mainly for two. First, a new area has emerged from within the forensic
sciences-that of forensic phonetics. As with all new specialties, it is necessary
to define it, identify its boundaries, justify its importance and compile a list of
the elements it encompasses. This book attempts to outline these several rela
tionships. Second, over the past decade I have become fascinated with forensics
in general and the rapidly expanded subarea of forensic phonetics in particular.
Admittedly, the latter field is one that is not as yet sufficiently appreciated-and
much more needs to be known about its nature and extent. Yet, I have found it to
be a most enjoyable area of study and my attempts to describe its domains were
quite informative. It was especially interesting to struggle with the interfaces
between forensic phonetics and related fields, and discover how they overlap.
Only a few comments will be made about the book's contents here in the
preface. For one thing, they are described in some detail in the first chapter.
Moreover, a detailed table of contents is provided; hence, information about the
main divisions (Le., "The Basics," "Problems with Tape Recordings," "Speaker
Identification," "Stress in Voice," and "Related Areas"), as well as the primary
sections within each of the individual chapters, can be found there. As the
reader will discover very early, I believe forensic phonetics to include such topics
as the enhancement of speech on tape recordings, the accurate decoding of
recorded speech, the authentication of tape recordings, speaker identification,
the detection of stress in voice and the identification of acoustic/recorded signa
tures of many types. Perhaps the territory should encompass yet other issues; in
any event, this book should serve as a first approximation of the field.
The second point I wish to make concerns my approach to the task of
presenting materials on the topics just cited. Since I recognize that the reader
often will be interested in only one or two of the several areas presented, I have
tried to write each chapter in a way that permits it to stand on its own. Thus,
after the four chapters that comprise "The Basics," I wrote each chapter (or at
least each section) as an independent element-and only later wove them into a
sequence by means of a single writing style, cross-referencing and interfacing
among the elements. This approach has led to a little redundancy in some places
vii
viii PREFACE
(see, for example, that between the "Basic Equipment" and "Electronic Sur
veillance" chapters; that among the chapters on the "Authentication of Tape
Recordings," "Machine/Computer Approaches," and "Signatures: Machine and
Acoustic"). So be it. I have found that whereas some readers can be briefed on a
specific area without reference to the rest of the book, others report that-when
they read the chapters in sequence-the occasional repetition simply serves to
underscore the point being made. Please also note that certain chapters are
organized in a different fashion than others. The reason for this is a practical
one; some of'the concepts presented are applied in nature and are· based on
practice rather than research, whereas others are strongly theoretical with a
great deal of data but few techniques available to the practitioner. Hence, the
approach used in writing the chapter on "Noisy Tapes" will be seen as different
from that employed for "Psychological Stress."
Third, I should like to emphasize here as well as later (see Chapter 1) that
this book is not an expose of any type. It is of little consequence to me which
"side" requests that I carry out certain tasks. If the data that result from my
investigations "aids" them, fine. If it does not, so be it. One must remember that
nearly every attorney and/or law enforcement agent is an advocate. Hence,
behaviors that might appear to constitute misconduct or marginal ethics usually
are the result of their enthusiasms or conviction that they are "in the right." In
short, most people in all the professions addressed by this book appear to be
both sincere and ethical. .
Finally, I would like to recognize the assistance and support of a number of
agencies and people. Indeed, whatever contributions I have been able to make
have resulted from the support I have received and the things-ordinarily good,
occasionally bad, and sometimes profound-that I have learned from other
people. The individuals to whom I am referring number in the hundreds; a few
are listed below. Moreover, the agencies that have provided me with research
support range from the National Institute of Justice to the Veterans Administra
tion, from the Office of Naval Research to the Army Research Office, from the
National Institutes of Health to the National Science Foundation, from the Inter
national Research Exchanges Board to the Fulbright Commission, and from the
Dreyfus to the Gould and the Voice Foundations. I thank all of them for their
kind consideration and support.
But, the interface with my colleagues has been even more important to me.
From James F. Curtis, I learned that precision in research is a must and how to
resist scientific fads; from Gordon Peterson, I learned the importance of being
scientifically thorough and always ethical; and from Joseph Wepman, how to be
honest and outspoken but not "play politics." The other dozen or so people who
have had the greatest impact on my work-and especially on this book-are W.
S. Brown, Jr., E. Thomas Doherty, Marylou P. Gelfer, W. J. Gould, J. W. Hicks,
Jr., Ruth Huntley, Martin Kloster-Jensen, Jens-Peter KOster, Wojceich Majewski,
Robert E. McGlone, William A. Sakow, Thomas Shipp, Gilbert C. Tolhurst, R. W.
Wendahl, Jiirgen Wendler-and my wife Patricia A. Hollien, who really should
be coauthor. Special thanks go to her, Kay Ervin and Kevin Hollien who assisted
mightily with the manuscript and figures, and to Robert Rieber for his patience.
Finally, there are my children-Brian and Kevin, Christine and Stephanie, Keith
and Karen; they contributed in many ways.
Contents
PART I THE BASICS
Chapter 1 Introduction 3
The Focus of the Book 5
Some Perspectives 6
What the Book Is All About 9
Chapter 2 Simple Acoustics 13
Introduction 13
Sound 14
The Nature of Sound 14
Sound Transmission 15
Frequency 17
Intensity 32
A Note on Psychoacoustics 38
Speech 38
Voice Quality 39
Vowel Quality 41
Chapter 3 Speech Characteristics 43
Introduction 43
How Speech Is Produced 43
The Power Supply 44
The Sound Source 46
The Articulatory System 51
Human Hearing 54
Anatomy of the Ear 54
Hearing Acuity 56
Phonetics 59
The Science of Speech 59
The Sounds of Speech 61
The Vowel 61
ix
x CONTENTS
Diphthongs 63
Transitions 64
Consonants 67
Coarticulation 67
Chapter 4 Basic Equipment 71
Introduction 71
Transducers 71
Microphones 72
Loudspeakers and Earphones 75
Tape Recorders 76
The Recording Process 77
The Recording Medium 77
The Playback Process 78
The Erase Process 78
Degaussers or Bulk Erasers 79
Tape Recorders Simplified 80
Care of Tape Recordings 84
Analysis Equipment 85
Wave Composition-Spectrography 86
Fundamental Frequency Analysis 93
Intensity Analysis 94
Temporal Measures 97
Computers 98
To Conclude 100
PART II PROBLEMS WITH TAPE RECORDINGS
Chapter 5 Electronic Surveillance 105
Introduction 105
The Body Bug 107
The Nature of the Body Bug 107
Problems with Body Bugs 108
Detection of Body Bugs and Countermeasures 111
Telephone Taps and Room Monitoring 112
Pen Registers 112
Telephone Taps 113
Room Monitors 116
From the Simple to the Sublime 124
Conclusions 125
Chapter 6 The Problem of Noisy Tape Recordings 127
Introduction 127
The Problem and Its Sources 128
Recording Procedures 128
Problems Resulting from a Noisy Environment 131
Basic Techniques of Speech Enhancement 133
Description:There are many reasons for writing a book; this one was conceived and devel oped mainly for two. First, a new area has emerged from within the forensic sciences-that of forensic phonetics. As with all new specialties, it is necessary to define it, identify its boundaries, justify its importance an
