It is a heavily interdisciplinary field at the crossroad between acoustics, neuroscience, and psychology.
[1] It is often related to one or many of these other fields: psychophysics, psychoacoustics, audiology, physiology, otorhinolaryngology, speech science, automatic speech recognition, music psychology, linguistics, and psycholinguistics.
Later in the 19th century, German physicist Hermann von Helmholtz wrote Sensations of Tone describing the founding concepts of psychoacoustics, i.e. the relationship between the physical parameters of a sound and the percept that it induces.
Psychoacoutics is primarily interested in the basic workings of the ear and is, therefore, mostly studied using simple sounds like pure tones.
In the 1950s, psychologists George A. Miller and J. C. R. Licklider furthered our knowledge in psychoacoustics and speech perception.