A Test of the Frequency Theory of Hearing
Hallowell Davis, S. Richard Silverman, D. R. McAuliffe · The Journal of the Acoustical Society of America · 1950
“Tone-pips” with a basic frequency of 2000 c.p.s. were produced by passing rectangular pulses of 14-msec. duration through two sound-effects filter sections in cascade. The high pass and the low pass cut-offs (18 db per octave) of each unit were set to 2000 c.p.s. The transducer was an Atlas PM 25 loudspeaker. The tone-pips appear on the oscilloscope as brief trains of waves that begin gradually and reach maximum amplitude at the third wave. The amplitude then falls off only a little less rapidly. A single pip sounds like a metallic click. When the pulses were repeated at 123 per second at sensation levels from 5 to 40 db all of our subjects reported hearing a “buzz.” Other descriptive terms used were “metallic,” “high pitched,” “continuously interrupted,” and “rough.” No listener, even when directly questioned and even when a pure tone of 123 per second had been sounded a few seconds previously for comparison, ever reported any trace of a low pitched component corresponding to 123 per second. Inasmuch as the frequency of nerve impulses in each nerve fiber is 123 per second under these conditions, the absence of a sensation of low pitch is contrary to the frequency theory of pitch perception and favors the place theory even for very low tones.