title: Influence of ultrahigh-frequency hearing thresholds on distortion-product otoacoustic emission levels at conventional frequencies.
abstract: This study examined the association between ultrahigh-frequency (UHF) hearing sensitivity and distortion-product otoacoustic emission (DPOAE) levels at conventional frequencies. Behavioral thresholds were measured from 2 through 16 kHz, and DPOAE levels were measured at discrete f2 frequencies between 2 through 8 kHz in 553 young normal-hearing adult male participants. A DPOAE frequency sweep was measured with primary stimulus levels of L1/L2 = 65/55 dB SPL and an f2/f1 of 1.2. Significant negative correlations, although weak, were found between UHF behavioral thresholds and DPOAE levels. As UHF behavioral thresholds worsened, DPOAE levels decreased at all frequencies. When the data were categorized into two groups, "better" and "worse" UHF behavioral thresholds, significant differences were apparent between the two groups for DPOAEs. Additionally, those with better UHF thresholds had better conventional thresholds compared to those in the worse UHF threshold group. The results of this age-restricted, large-sample-size study confirm and augment findings from earlier studies demonstrating that UHF hearing sensitivity has some influence on DPOAE measures at frequencies from 2 through 8 kHz with moderate stimulus levels. However, because those with better UHF thresholds also had better conventional thresholds and the significant correlations found were weak, this work supports the importance of UHF hearing testing in conjunction with otoacoustic emission measures to identify basal cochlear insults not evident from behavioral testing at conventional frequencies.
authors.affiliation: San Diego State University, School of Speech, Language, and Hearing Sciences, 5500 Campanile Dr., San Diego, CA 92182-1518, USA. ldreisba@mail.sdsu.edu
authors.forename: Laura Elizabeth
authors.initials: LE
authors.lastname: Dreisbach
authors.forename: Peter
authors.initials: P
authors.lastname: Torre
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kramer
authors.forename: Richard
authors.initials: R
authors.lastname: Kopke
authors.forename: Ronald
authors.initials: R
authors.lastname: Jackson
authors.forename: Ben
authors.initials: B
authors.lastname: Balough
mesh_terms: D000158:Acoustic Impedance Tests; D000293:Adolescent; D000328:Adult; D001309:Auditory Threshold / Q000502:physiology*; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D008889:Military Personnel; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D038781:Otoscopy; D010897:Pitch Discrimination / Q000502:physiology*; D055815:Young Adult