Dichotic pitch

When continuous white noise (with a frequency content below about 2000 Hz) is presented by headphones to the left and right ear of a listener, and given a particular interaural phase relationship between the left and right ear signals, a sensation of pitch (psychophysics) may be observed. Thus, stimulation of either ear alone gives rise to the sensation of white noise only, but stimulation of both ears together produces pitch. Therefore, as a special case of dichotic listening, such a pitch is called dichotic pitch or binaural pitch. Generally, a dichotic pitch is perceived somewhere in the head amidst the noisy sound filling the binaural space. To be more specific, the dichotic pitch is characterized by three perceptual properties: pitch value, timbre, and in-head position (lateralization). Experiments on dichotic pitch were motivated in the context of the study of pitch in general, and of the binaural system in particular, relevant for sound localization and separation of competing sound sources (see cocktail party effect). In the past, various configurations of dichotic pitch were studied and several auditory models were developed. The great challenge for psychophysical and physiological acoustics is to predict both the pitch value and pitch-image position in one model. For more information, references, audio demos etc. see more.