Comparing behavioral and physiological measures of combination tones: sex and race differences.
Both distortion-product otoacoustic emissions (DPOAEs) and performance in an auditory-masking task involving combination tones were measured in the same frequency region in the same ears. In the behavioral task, a signal of 3.6 kHz (duration 300 ms, rise/fall time 20 ms) was masked by a 3.0-kHz tone (62 dB SPL, continuously presented). These two frequencies can produce a combination tone at 2.4 kHz. When a narrowband noise (2.0-2.8 kHz, 17 dB spectrum level) was added as a second masker, detection of the 3.6-kHz signal worsened by 6-9 dB (the Greenwood effect), revealing that listeners had been using the combination tone at 2.4 kHz as a cue for detection at 3.6 kHz. Several outcomes differed markedly by sex and racial background. The Greenwood effect was substantially larger in females than in males, but only for the White group. When the magnitude of the Greenwood effect was compared with the magnitude of the DPOAE measured in the 2.4 kHz region, the correlations typically were modest, but were high for Non-White males. For many subjects, then, most of the DPOAE measured in the ear canal apparently is not related to the combination-tone cue that is masked by the narrowband noise.
Department of Psychology and Center for Perceptual Systems, University of Texas, Austin, 108 East Dean Keeton, A8000, Austin, Texas 78712-1043, USA. mcfadden@psy.utexas.edu
Dennis
D
McFadden
Edward G
EG
Pasanen
Erin M
EM
Leshikar
Michelle D
MD
Hsieh
Mindy M
MM
Maloney
D000161:Acoustic Stimulation; D001299:Audiometry; D001309:Auditory Threshold; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise / Q000009:adverse effects; D017084:Otoacoustic Emissions, Spontaneous; D010470:Perceptual Masking; D010898:Pitch Perception; D011571:Psychoacoustics; D044469:Racial Groups; D012737:Sex Factors; D017603:Signal Detection, Psychological; D055815:Young Adult