Psychoacoustics is essentially the study of the perception of sound. This includes how we listen, our psychological responses, and the physiological impact of music and sound on the human nervous system. In the realm of psychoacoustics, the terms music, sound, frequency, and vibration are interchangeable, because they are different approximations of the same essence. The study of psychoacoustics dissects the listening experience.
Traditionally, psychoacoustics is broadly defined as "pertaining to the perception of sound and the production of speech." The abundant research that has been done in the field has focused primarily on the exploration of speech and of the psychological effects of music therapy. Currently, however, there is renewed interest in sound as vibration.
An important distinction is the difference between a psychological and a neurological perception. A song or melody associated with childhood, a teenage romance, or some peak emotional experience creates a memory-based psychological reaction. There is also a physiological response to sounds, however. Slightly detuned tones can cause brain waves to speed up or slow down, for instance. Additionally, soundtracks that are filtered and gated (this is a sophisticated engineering process) create a random sonic event. It triggers an active listening response and thus tonifies the auditory mechanism, including the tiny muscles of the middle ear. As a result, sounds are perceived more accurately, and speech and communication skills improve. While a psychological response may occur with filtered and gated sounds, or detuned tones, the primary effect is physiological, or neurological, in nature.
Research on the neurological component of sound is currently attracting many to the field of psychoacoustics. A growing school of thought - based on the teachings of the French doctor Alfred Tomatis - values the examination of both neurological and psychological effects of resonance and frequencies on the human body.
Thanks to the ground breaking findings of Dr. Tomatis, we have come to understand the extraordinary power of the ear. In addition to its critical functions of communication and balance, the ear's primary purpose is to recycle sound and so recharge our inner batteries. According to Tomatis, the ear's first function in utero is to govern the growth of the rest of the physical organism. After birth, sound is to the nervous system what food is to our physical bodies: Food provides nourishment at the cellular level of the organism, and sound feeds us the electrical impulses that charge the neocortex. Indeed, psychoacoustics cannot be described at all without reference to the man known as the "Einstein of the ear."
In the realm of application-specific music and sound, psychoacoustically-designed soundtracks revolve around the following concepts and techniques:
• Intentionality (focused application for specific benefit)
• Resonance (tone)
• Entrainment (rhythm)
• Pattern Identification (active listening or passive hearing)
• Sonic Neurotechnologies (highly specialized sound processing)