Sound.psychoacoustics - Abstract and Review

Introduction

One  question that has long been argued over, by philosophers as well as
children, is whether a tree falling in a forest where nobody can hear it fall
will actually make a sound. This article defines sound as mechanical vibrations
traveling through the air or some other medium at a frequency to which the human
ear is sensitive. Therefore, it would answer the above question in the
affirmative, arguing that the mechanical vibrations composing a sound wave do
exist whether or not anyone is present to hear them.

The science of sound is called acoustics, a word derived from the Greek akoustos,
meaning "hearing." Beginning with its origins in the study of mechanical
vibrations and the radiation of these vibrations through mechanical waves,
acoustics has had important applications in almost every area of life. It has
been fundamental to many developments in the arts--some of which, especially in
the area of musical scales and instruments, took place after long experimentation
by artists and were only much later explained as theory by scientists. For
example, much of what is now known about architectural acoustics was actually
learned by trial and error over centuries of experience and was only recently
formalized into a science. Other applications of acoustic technology are in the
study of geologic, atmospheric, and underwater phenomena. [Index]
Psychoacoustics, the study of the physical effects of sound on biological
systems, has been of interest since Pythagorus first heard the sounds of
vibrating strings and of hammers hitting anvils in the 6th century BC, but the
application of modern ultrasonic technology has only recently provided some of
the most exciting developments in medicine. Even today, research continues into
many aspects of the fundamental physical processes involved in waves and sound
and into possible applications of these processes in modern life.

This article begins with an explanation of the physical properties of waves and
sound and then discusses applications of acoustics to the areas of science,
technology, the arts, and medicine. Also discussed are the related sciences of
ultrasonics and infrasonics, which technically are not sound because they are not
perceived by the ear but which have very important applications in modern
technology.

Sound waves follow physical principles that can be applied to the study of all
waves; these principles are discussed thoroughly in the Macrop²dia article
MECHANICS. The article SENSORY RECEPTION explains in detail the physiological
process of hearing--that is, receiving certain wave vibrations and interpreting
them as sound.

This abstract and review was obtained from OnLine subscription services -
courtesy of Charles Turley.