Psychoacoustics is the study of the relationship between
physical sounds and the brain’s interpretation of them. Until
recently, psychoacoustics has devoted more attention to the
behaviour of the peripheral auditory system than to the details
of cognitive processing. The discipline is a branch of
psychophysics in that it is interested in the relation between
sensory input stimuli and the behavioural or psychological
response that they provoke. Because of individual variations in
observed responses, statistical results are most often achieved.
Some of the traditional psychoacoustic concerns involve the
perception of pitch, loudness, volume and timbre. Contemporary
work involves higher level concepts such as auditory percepts,
streaming, and auditory scene analysis. (Source: Barry Truax -
Handbook for Acoustic Ecology CD-ROM Edition. Cambridge Street
Publishing, 1999 - CSR-CDR 9901)