Binaural recordings of 400 Hz pure-tones played from a loudspeaker in my dining room. Analyses show that ITD and ILD resemble ‘ideal’ values before recent reflections arrive, after which values begin to drift. Contributions to spatial hearing are primarily from cues emerging at the onsets of the tones, before early reflections arrive.
Interaural level differences (ILDs) at the times of zero-crossings after passing each recording through a 400 Hz auditory filter (circles in upper panel). Red and blue lines in the lower panel show right and left amplitude envelopes, respectively.
- • ILDs fluctuate broadly prior to when each pure-tone starts (before 0 ms).
- • Values then contract for ~20 ms as amplitude rises, as would occur in a quiet, anechoic, setting.
- • Due to acoustic reflections and background sounds, values begin to drift and fluctuate after ~20 ms, becoming more pronounced over the duration of each tone (200 ms) .