Factors affecting a loudness asymmetry in real-room reverberation.

Abstract

Narrowband stimuli with envelopes that have a slow-attack and a fast-decay (S-F) are judged to be louder than temporally-reversed, equal-energy versions of the stimuli (i.e., fast-attack and slow-decay, or F-S). We have found that this perceived loudness asymmetry is also apparent with real-room reflection patterns using dichotic presentation of sounds processed with binaural room impulse responses. These findings are consistent with the idea that the energy in the decaying tails of stimuli is discounted from loudness judgments because they are perceptually attributed to room reverberation. These results might therefore arise from the same perceptual mechanism that compensates for reverberation in speech which seems to operate within but not between frequency bands. Here, we ask whether the loudness asymmetry is similarly a “band-by-band” mechanism using conditions where loudness comparisons are made between S-F and F-S stimuli that are in the same or in different frequency bands.