Development of a 500-Hz masking-level difference protocol for clinic use.
The purpose of this series of experiments was to develop a simple, 500-Hz masking-level difference (MLD) protocol that could be implemented easily in the clinic to assess auditory perceptual abilities using an audio compact disc. Five, 300-ms tones with 250-ms intertone intervals were embedded in 3-s bursts of 200-800 Hz noise presented at 42.2-dB pressure-spectrum level with 4-5 s interstimulus intervals. The homophasic and antiphasic conditions were interleaved with the signal-to-noise ratios decreasing in 2-dB steps. A single-interval, "yes/no" response task was used. Three experiments were performed on 24-28 listeners with normal hearing. The mean SoNo thresholds (58.1- to 59.5-dB SPL) and the mean SpiNo thresholds (45.1- to 46.0-dB SPL) produced approximately 13-dB MLDs. Experiment 3 included a SoNpi condition that had a mean threshold of 48.8-dB SPL and a 10.0-dB MLD. The mean test, retest of the SoNo and SpiNo thresholds on 15 listeners was < 0.5 dB. Over the three experiments, 95% of the listeners had SpiNo MLDs that were > or = 10 dB.
Wilson
Richard H
RH
James H. Quillen VA Medical Center, Mountain Home, Tennessee 37684, USA.
Moncrieff
Deborah W
DW
Townsend
Elizabeth A
EA
Pillion
Amanda L
AL
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception; D016250:Compact Disks; D005260:Female; D006309:Hearing / Q000502:physiology; D006801:Humans; D008297:Male; D009622:Noise; D010470:Perceptual Masking / Q000502:physiology*; D011571:Psychoacoustics; D017603:Signal Detection, Psychological