Frequency Coding And Auditory Space Perception

Three primary dimensions of sensations associated with sounds with periodic waveforms Pitch, loudness and timbre. Pitch - sensation of "altitude" or "height" of a tone. Loudness - sensation of "intensity" of a tone. Timbre - quality of a sound.

Psychological Dimension Associated Physical Dimension Pitch Frequency Loudness Amplitude Timbre Spectrum

Historically, there have been two major approaches to frequency coding. Frequency theory (or timing) and Place theory - both focused on the basilar membrane

Auditory Localization

Interaural delays for three different sound directions

Sound waves coming from the right side reach the right ear first, and there will be a large interaural delay before the sound propagates to the left ear.

With high frequency sound the head will cast a sound shadow

Slight asymmetries in arrival times between the two ears can be used to locate the lateral position of a stimulus. Delay lines and coincidence detectors may perform this computation.