Sharpness as an Attribute of the Timbre of Steady Sounds

A factorial investigation on verbal attributes of timbres of steady sounds had shown that the attribute sharpness represented the factor carrying most of the variance (v. Bismarck [3]). In the present experiment, sharpness was scaled by several standard psychophysical methods in order to test its consistent measurability. Sharpness of both noise and harmonic complex tones, which were nearly equal in pitch and loudness and differed e. g. in the limiting frequencies and slopes of their spectral envelopes, could be determined quantitatively with different methods. Doubling, halving and directly comparing sharpness yielded internally consistent results. Sharpness increased with the upper and lower limiting frequency as well as the slope of the spectral envelope. The fine structure of the spectrum showed a comparatively small effect on sharpness.

Exploratory experiments were aimed at scaling the sharpness of sounds differing strongly in loudness and pitch. Although some of these measurements revealed large scatter in the responses, sharpness appeared as an attribute distinguishable from pitch and loudness. The observed relations between sharpness and the investigated sound parameters could be approximated by a weighted first moment of the loudness-critical band rate-pattern.