Complex spectral patterns with interaural differences: Dichotic pitch and the 'Central Spectrum'

A complex sound’s amplitude and phase spectra are likely to be different at one ear relative to the other ear when the sound arrives at the two ears. This chapter describes experiments involving broadband stimuli in which narrow bands are presented with interaural differences of amplitude or phase. Listeners perceive a pitch for these stimuli that corresponds to the spectral location of the band of interaurally shifted components. These stimuli produce a version of the Cramer-Huggins dichotic pitch. A psychophysical procedure was developed to estimate the salience of the dichotic pitches for a variety of stimulus conditions. The results are described in terms of a ‘Central Spectrum’ and are discussed in relationship to conditions that yield binaural masking-level differences (BMLD).