Psychoacoustics is the study of how humans perceive and interact with sound. Fields of study within psychoacoustics include pitch perception, sound localization, and musical acoustics. Use of psychoacoustics can help sound engineers create more realistic sound space experiences for music, movies, and concerts. In medicine, psychoacoustics can help medical professionals identify and treat causes of hearing loss or sound localization malfunction. Tests performed when studying psychoacoustics often examine the nature of the sound as well as brain activity that occurs in response to sound.
In sound science, acoustics can refer anything related to sound. In casual conversation, the word acoustics is most often used to refer to the way sound echos within a room, or to refer to an instrument that operates without electronic amplification of sound. Musical acoustics is sound study within the field of music, which studies activities related to listening to, perceiving, and performing music. Psychoacoustics involves the interaction between sound and the human brain. A related field, neuromusic, examines the interaction between music and the brain. This includes studying how normal people process music, how people with disorders process music, and particularly how musicians process music, with specific focus on musical training and musical memory.
Sound localization is a person's ability to locate the source of a sound. This part of psychoacoustics studies how a person's brain uses sounds reaching both ears to determine sound source location. The brain is able to locate a sound source based on the differences between what is heard in each ear as a result of the position of a person's head and his ears. Factors that can influence sound localization include the shape of the skull, the space between the person's ears, and any external environmental echos.
Pitch perception is the ability to tell the difference between different frequencies of sound, which are organized into classes of pitches. In music, pitches come in groups labeled A through G. An octave consists of eight whole steps from one A to the next A. Each group of notes contains 12 half steps. A person who can perceive and label pitches accurately without the use of an outside instrument like a tuning fork is said to have perfect pitch. While perfect pitch is helpful when playing most instruments, it is most vital when singing and playing instruments like trombone, or fretless stringed instruments that have no predefined pitch reference points and rely on a player's ability to play an accurate pitch on his own.