ABSTRACT
The binaural precedence effect is often spoken of as evidence of neural suppression of echoes. This chapter reviews a detection-based technique designed to measure the amount of binaural information actually derived from successive portions of a signal. The work shows that, for high stimulus rates (tonal frequencies or rates of modulation), the effectiveness of each part of a stimulus is less than the part that precedes it. The process responsible for this loss in binaural information is dubbed binaural adapta tion. It is well described with compressive power functions whose exponents decline as the stimulus rate is increased. It has been found with a variety of stimuli such as pure tones, noise, sinusoidal amplitude modulation, and trains of clicks. Experiments cited here discuss the level of auditory processing at which binaural adaptation takes place; these point to monaural channels in the auditory periphery, prior to binaural interaction. Other experiments describe a rapid recovery from binaural adaptation in response to a variety of extraneous acoustical triggers. Together, these results are contrasted with binaural precedence, which is argued to be a more cognitive process residing in a more central part of the auditory system. The general conclusion is that these two processes rely on separate mechanisms.
