title: Effects of non-simultaneous masking on the binaural masking level difference.
abstract: The present study sought to clarify the role of non-simultaneous masking in the binaural masking level difference for maskers that fluctuate in level. In the first experiment the signal was a brief 500-Hz tone, and the masker was a bandpass noise (100-2000 Hz), with the initial and final 200-ms bursts presented at 40-dB spectrum level and the inter-burst gap presented at 20-dB spectrum level. Temporal windows were fitted to thresholds measured for a range of gap durations and signal positions within the gap. In the second experiment, individual differences in out of phase (NoSπ) thresholds were compared for a brief signal in a gapped bandpass masker, a brief signal in a steady bandpass masker, and a long signal in a narrowband (50-Hz-wide) noise masker. The third experiment measured brief tone detection thresholds in forward, simultaneous, and backward masking conditions for a 50- and for a 1900-Hz-wide noise masker centered on the 500-Hz signal frequency. Results are consistent with comparable temporal resolution in the in phase (NoSo) and NoSπ conditions and no effect of temporal resolution on individual observers' ability to utilize binaural cues in narrowband noise. The large masking release observed for a narrowband noise masker may be due to binaural masking release from non-simultaneous, informational masking.
authors.affiliation: Department of Otolaryngology∕Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA. ebuss@med.unc.edu
authors.forename: Emily
authors.initials: E
authors.lastname: Buss
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Hall Iii
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D001309:Auditory Threshold; D003463:Cues; D006801:Humans; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D015588:Observer Variation; D010470:Perceptual Masking; D011571:Psychoacoustics; D015203:Reproducibility of Results; D017603:Signal Detection, Psychological; D013997:Time Factors; D013998:Time Perception; D055815:Young Adult