Asymmetrical perception of dynamic changes in rising and falling sounds

Abstract

Previous studies have demonstrated a perceptual enhancement effect for rising sounds and interpreted at an ecological level the enhancement of rising sounds as a perceptual bias towards an approaching auditory object [Neuhoff, Nature (London) 395, 123 (1998)]. This study has not been independently replicated and both its interpretation and mechanisms are still debatable. The present study was aimed at replicating and extending the Neuhoff study by measuring just-noticeable differences in intensity for rising tone and falling sounds. Pure tones, harmonic complex tones, and white noise were used as the stimuli. Similar to Neuhoff’s study, subjects had to estimate by rating on a scale the loudness changes heard corresponding to rising or falling sounds. In addition, they had to discriminate between either a rising or falling sound and a steady-state sound or discriminate between two rising or falling sounds. Both magnitude estimation and objective discrimination data were consistent with Neuhoff’s results, showing that rising sounds needed 2 and 7 dB less than falling sounds in discriminating them from a steady-state sound and from a similarly dynamically changing sound, respectively. Mechanisms related to this perceptual asymmetry will be discussed.