The psychophysical basis of monaural localization.

Listeners were required to locate, monaurally, noise bursts emanating from the horizontal plane ipsilateral to the functioning ear. Loudspeakers were positioned from 0 through 180 degrees azimuth, separated by 15 degrees. Stimulus bandwidth was 1.0 kHz, and centered at 4.0-14.0 kHz in steps of 0.5 kHz. The location judgments were governed by the frequency composition of the stimuli, not by their place of origin. With a miniature microphone positioned at the entrance of the external ear canal, the relative amplification provided by the pinna was obtained for the stimuli employed in the localization tests. For each differently centered noise burst, that loudspeaker position re other positions which was associated with the greatest amplification of the stimulus was the one most likely to have been chosen as the source of that stimulus during the localization tests.