Post-transient shifts in auditory lateralization: effects of target level

Exposing one ear to a series of brief 80 dB sound pressure level (SPL) inducing tones reduces the tendency to lateralize subsequent target tones to that ear and shifts the point of subjective equality (PSE) toward the unexposed ear. Furthermore, targets with average SPLs of 60 and 80 dB at the two ears showed similar changes in PSE. These results support and extend earlier findings of Arieh and Marks (2007). Percept. Psychophys. 69, 523-528 and suggest the presence of a mechanism, located at least partially before the site of binaural integration, that depresses the magnitude of intensity information from the ear in response to moderately intense transient stimuli. Assuming that lateralization depends on the ratio of the magnitude of intensity information from the two ears that reach the central integrator, the results imply that the inducer reduced the representations of magnitude of 60 and 80 dB test tones in equal proportion.