Relation between Hearing Threshold and Duration for Tone Pulses

Abstract

This paper deals with some measurements concerning the threshold versus duration for tone pulses. A new hypothesis introduced: Switching on a tone pulse of intensity I results in an effect s somewhere in the hearing pathway, that approaches its final value asymptotically according to an exponential function; this final value is proportional to I; perception occurs when s exceeds a critical value s 0. The experiments show that this hypothesis gives a better description than the hypotheses thus far used. The time constant varies from ca 375 msec at 250 cps to ca 150 msec at 8000 cps. For short pulse durations the data deviate from the hypothesis. This deviation can be explained by the assumption that energy integration around each frequency is restricted to a fixed band width. A formula is derived which gives a correction to the mentioned relationship for short durations. In this way the band width at the different test frequencies could be determined. The general course of this band width as a function of frequency agrees with the “Kopplungsbreite” after Gässler.