My interest in pitch stems in part from my work on Fundamental Frequency estimation, and in part from a visit I made to Adrian Fourcin's The Fourcin pitch is obtained by presenting white noise to both ears, but with a particular inter-aural phase. The sound at each ear contains absolutely no cue on which to base the pitch, so the pitch must therefore arise from interactions happening "between the ears", within the auditory system. This put me from on the side of "time" from the outstart. For those who do not know, there is a deep and ancient quarrel in the realm of hearing, between "place" and "time", dating back a hundred years to a terrible fight between Helmholtz and Ohm on one side, and Seebeck on the other.

A young student reading papers on hearing is bewildered at first. Why are they studying that? And why are they so careful with their words? The answer comes only once one becomes aware of the terrible feud. The key papers are Schouten (1970) and de Boer (1979) (ah, that I could write like them...) and Evans (1978). Moore's textbook is also a good place to look for a modern perspective of an ancient battlefield.

According to the tenants of "place", pitch is perceived as a result of frequency analysis in the cochlea. In its earliest form, the relevant cue was the fundamental frequency, the lowest non-DC component in the spectrum. Later forms used the pattern of the entire spectrum. According to the tenants of "time", the relevant aspect is the period of the sound waveform, that is represented in the rhythm of neural discharges carried from the ear to the auditory system. In the case of Fourcin pitch, "place" mechanisms cannot work, one must invoke "time".

[to be continued]