The effect of noise on time-intensity trading in lateralization.
A two-interval forced-choice lateralization task was used to determine interaural delays and interaural amplitude ratios which, when opposed in quiet, led to chance lateralization; the opposed cues formed time-intensity trades. Three types of signal were used: (1) 20-microseconds clicks; (2) 250-ms bursts of a 305 Hz tone; and (3) 250-ms bursts of 3965 Hz carrier amplitude modulated to a depth of 100% at a modulation rate of 305 Hz. The addition of various levels of broad-band white noise did not influence the relative effectiveness of the two lateralization cues with pure tone signals; however, the addition of noise to clicks and to AM waveforms led to lateralization judgements in which the cue based on interaural delay appeared to be less effective than in quiet.
D000161:Acoustic Stimulation; D001307:Auditory Perception; D006801:Humans; D009622:Noise; D013017:Sound Localization; D013997:Time Factors