Lateralization and Detection of a Tonal Signal in Noise
Dennis McFadden · The Journal of the Acoustical Society of America · 1969
The ability to lateralize a tonal signal against a white-noise background was investigated by presenting that signal at different intensities to the two ears and asking the listener to indicate which ear received the more intense signal. The signal (500 cps, 250 msec) was gated on every trial during the single observation interval, and the more intense signal was equally likely to be presented to the leaf ear as to the right. Both the interaural phase relation of the signal and the magnitude of the interaural intensive difference were variables of interest. For signals both in phase (S0) and 180° out of phase (Sπ), six-point psychometric functions were determined with interaural intensive differences of 3. 6. and 12 dB In addition, detection functions were obtained for each of these interaural conditions using a single-interval forced-choice technique. Particularly for the smaller interaural intensive differences. S0 and Sπ signals led to lateralization functions of quite different forms. Noise: in phase interaurally (N0), continuous 44 dB SPL/cycle.