Lateral position of dichotic pitches can be substantially affected by interaural intensitive differences.

Abstract

Three listeners used an acoustic pointer to match the intracranial position of dichotic pitches presented with interaural intensitive differences (IIDs). Unlike data reported previously [Raatgever, ‘‘Binaural time processing and time-intensity trading,’’ in Psychophysics, Physiology, and Behavioural Studies in Hearing, edited by G. van den Brink and F. A. Bilsen (Delft U.P., Delft, The Netherlands, 1980), pp. 425–453], the intracranial position of the dichotic image was moved substantially by IIDs. Large effects of IIDs were found in a variety of stimulus conditions, including one investigated by Raatgever. When the dichotic stimuli were not pulsed, but were presented continuously and turned off only when the acoustic pointer was presented, one of the listeners produced data like those previously reported by Raatgever. It appears that intracranial images produced by stimuli which support dichotic pitches, like images produced by other binaural stimuli, can be affected substantially by IIDs. Consequently, in terms of lateralization, it does not appear necessary to maintain a theoretical cleavage between images produced by dichotic pitches (previously thought to be influenced only by ITDs) and images produced by other binaural stimuli. [Work supported by Grant No. 5 RO1 DC00234-13 from the National Institute on Deafness and other Communication Disorders, NIH.]

Lateralization of Huggins pitch

“…In this method listeners assign numerical values, according to a fixed scale, to their estimates of the lateral positions of the pitch images. Previous experiments have also measured the lateralization of HP ͑Raatgever and Bilsen, 1977Bilsen, , 1986Grange and Trahiotis, 1996;Akeroyd and Summerfield, 2000͒, but those experiments were indirect. They matched the lateral position of HPs by varying an interaural parameter of some other form of stimulus, used as an acoustic pointer.…”