Le Chatelier's principle in sensation and perception: fractal-like enfolding at different scales.

Le Chatelier's principle asserts that a disturbance, when applied to a resting system may drive the system away from its equilibrium state, but will invoke a countervailing influence that will counteract the effect of the disturbance. When applied to the field of sensation and perception, a generalized stimulus will displace the system from equilibrium, and a generalized adaptation process will serve as the countervailing influence tending to reduce the impact of the stimulus. The principle applies at all levels, from the behavioral to the neural, the larger enfolding the smaller in fractal-like form.

A mathematical exploration of the mystery of loudness adaptation.

Loudness adaptation, or the decrease in perceived loudness of a steady, prolonged tone is rather a mysterious phenomenon. When measured by one technique (utilizing both ears), loudness of an extended tone will decrease by as much as 35 decibels; when measured by another technique (using only a single ear), loudness does not adapt at all regardless of how long the tone persists. The mystery is even more intriguing.

Loudness adaptation measured by the simultaneous dichotic loudness balance technique differs between genders.

Loudness adaptation was measured using the classic simultaneous, dichotic loudness balance technique. A 6-min continuous tone was introduced using headphones to a participant's adapting ear. Immediately upon presentation of the tone and at 1-min intervals, participants adjusted the sound level of a tone of the same frequency in the contralateral control ear until both tones sounded equally loud.

Identification variability as a measure of loudness: an application to gender differences.

It is well known that discrimination response variability increases with stimulus intensity, closely related to Weber's Law. It is also an axiom that sensation magnitude increases with stimulus intensity. Following earlier researchers such as Thurstone, Garner, and Durlach and Braida, we explored a new method of exploiting these relationships to estimate the power function exponent relating sound pressure level to loudness, using the accuracy with which listeners could identify the intensity of pure tones.