Eric J. Heller - Why You Hear What You Hear: An Experiential Approach to Sound, Music, and Psychoacoustics

Why You Hear What You Hear

An Experiential Approach to Sound, Music, and Psychoacoustics

Eric J. Heller

PRINCETON UNIVERSITY PRESS
Princeton and Oxford

Copyright 2013 by Princeton University Press
Published by Princeton University Press, 41 William Street,
Princeton, New Jersey 08540
In the United Kingdom: Princeton University Press, 6 Oxford Street Woodstock,
Oxfordshire OX20 1TW
press.princeton.edu

All Rights Reserved

Library of Congress Cataloging-in-Publication Data

Heller, Eric Johnson.
Why you hear what you hear: an experiential approach to sound, music, and psychoacoustics/
Eric J. Heller.
p. cm.
Includes bibliographical references and index.
ISBN 978-0-691-14859-5 (hardback: alk. paper)
1. Hearing. 2. SoundTransmissionMeasurement. 3. Psychoacoustics.
I. Title.
QP461.H395 2012
612.85dc23

2011053479

British Library Cataloging-in-Publication Data is available

This book has been composed in Minion Pro and Myriad Pro

Printed on acid-free paper.

Typeset by S R Nova Pvt Ltd, Bangalore, India
Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

To Sharl

No book about vision and visual art is devoid of diagrams and reproductions, yet books about sound and music are traditionally mute. It has been possible to print images in books for centuries, but conveying sound has historically been much more difficult.

The situation started to change when the Laboratory of Psychophysics of Harvard University (active from 1940 to 1972) under Professor Stanley Smith Stevens produced and recorded 20 demonstrations on psycho-acoustics, plus an explanatory booklet. Later Houtsma, Rossing, and Wagenaars created a set of improved demonstrations on a CD illustrating many important psychoacoustic phenomena. Available now on the Internet, their work has been recommended listening by many texts. This was a good beginning, but new technology has made it possible and relatively easy to do far more.

This book is integrated with many example sound files and interactive applets that generate and analyze sound. They are available on the books website, whyyouhearwhatyouhear.com. If a picture is worth 1000 words, so too is a sound file. Sounds and effects created and analyzed on the fly with well-conceived applets are worth 10,000 words. Computer animation, Java, MAX patches, Mathematica applets, sound processing and analysis tools (such as Audacity) not to mention the World Wide Web, all flow into crisp display screens and high-fidelity headphonesat little or no expense. Any book on sound and acoustics that doesnt take advantage of these technological miracles is missing a huge opportunity. The many excellent books of the past, no matter how good they otherwise are, cannot provide the reader with the firsthand interactive knowledge and listening experience we integrate into this book. Yet we hope to have given new life to some parts of these older classics, by providing interactive examples illustrating some of their major lessons.

If nothing had evolved in the last 20 years, it would be quite presumptuous to offer a conceptually higher level book about acoustics to the nonspecialist. But things have evolved: anyone with a laptop has a fully portable sound laboratory and recording studio that might have cost hundreds of thousands of dollars not so long ago. Now it is possible to achieve true understanding by showing and doing, at ones own desk or anywhere a personal computer is taken. We seize this new opportunity to actually explain sound to the nonspecialist, rather than to present descriptions or mnemonics received from on high. This approach certainly puts more demands on the reader, but the reward is an intuitive understanding previously reserved for the best sound engineers and acousticians.

In spite of its long history, acoustics is still wide open to discovery. The level of this book is only a step away from original research, and many times we point the way to something that needs further investigation. With the approach we take here and the new tools available, readers can experience the sense of discovery that scientists crave. New phenomena or interesting variants on known effects can be exposed using the tools and point of view provided here. You will certainly learn much about your own hearing, including whether it is normar and whether you have special abilities or tendencies, such as the ability to listen analytically rather than holistically to complex tones.

Musical instruments are understood through representative cases that focus on the way these instruments actually work. We trust the reader to extrapolate from trumpet to trombone, from violin to viola. This focus enriches the understanding of the important physical effects at play and explains rather than describes the instrument. Coupled resonators, Fourier analysis, autocorrelation, impulse response, impedance mismatch and reflection at open tube ends and toneholes, wall losses, phase of drives near resonance, and launching of sound by accelerating surfaces all help explain the effects of a mouthpiece, bell, violin body, the phase of the lip buzzing on a trumpet, the bending of notes on a sax, and so on.