Psychoacoustics

Psychoacoustics is the study of subjective human perception? of sounds. Effectively, it is the study of psychology of acoustical perception.

In many applications of acoustics and audio signal processing it is neccessary to know what humans actually hear. Air pressure waves, that is, sound, can be accurately measured with sophisticated equipment. However, knowing how these waves are mapped into thoughts in the brain is not trivial. Sound is a continuous analog signal which can contain, in theory, an infinite amount of information. There is an infinite amount of frequencies and each of contain have both magnitude and phase information.

Recognizing features important to perception enables scientists and engineers to concentrate on audible features and ignore less important features of the involved system. It is important to note that the question of what humans hear is not only a physiological question of features of the ear? but very much also a psychological issue.

Yet to be done:

• Frequency range approx. 20Hz to 20kHz
• Loudness, that is, percieved volume
• Shading effects (is shading the correct term?)
  • intensity shading
  • pitch shading
  • temporal shading
  • others?
• Perception of non-existent sounds, such as, missing fundamental frequency. Compare to telephone which transmits 500Hz to 3500Hz.
• 3D perception

See also:

• audio compression
• [speech recognition]?
• source separation
• [Bark scale]?