Submilisecond acoustic pulses: effective pitch and Weber-Fechner law in discrimination of duration times

Abstract

The enclosed tests demonstrate that an effective pitch can be attributed to acoustic signals shorter then tenths of milliseconds. A power-law dependence of this pitch on the signal's duration time is found for subjects tested with Gaussian pulses. The discrimination threshold for the pulse duration time reported on the basis of the effective pitch increases proportionally to the duration time itself, i.e. it follows the Weber-Fechner law. A model based on the "Helmholtz's harp" idea, i.e. a series of damped resonators tuned in the audible range of frequencies, reveals the mechanism of producing a maximum in the filtered spectrum of the pulse. This corroborates the power law in the dependence of the position of the maximum on the duration time of the pulse. The model indicates a possibility of designing a manmade device dedicated to determination of the durations so short that they are inaccessible by direct measurements.