title: Distortion-product otoacoustic emission suppression tuning curves in humans.
abstract: Distortion-product otoacoustic emission (DPOAE) suppression data as a function of suppressor level (L(3)) for f(2) frequencies from 0.5 to 8 kHz and L(2) levels from 10 to 60 dB sensation level were used to construct suppression tuning curves (STCs). DPOAE levels in the presence of suppressors were converted into decrement versus L(3) functions, and the L(3) levels resulting in 3 dB decrements were derived by transformed linear regression. These L(3) levels were plotted as a function of f(3) to construct STCs. When f(3) is represented on an octave scale, STCs were similar in shape across f(2) frequency. These STCs were analyzed to provide estimates of gain (tip-to-tail difference) and tuning (Q(ERB)). Both gain and tuning decreased as L(2) increased, regardless of f(2), but the trend with f(2) was not monotonic. A roughly linear relation was observed between gain and tuning at each frequency, such that gain increased by 4-16 dB (mean ≈ 5 dB) for every unit increase in Q(ERB), although the pattern varied with frequency. These findings suggest consistent nonlinear processing across a wide frequency range in humans, although the nonlinear operation range is frequency dependent.
authors.affiliation: Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA. Michael.Gorga@boystown.org
authors.forename: Michael P
authors.initials: MP
authors.lastname: Gorga
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Neely
authors.forename: Judy
authors.initials: J
authors.lastname: Kopun
authors.forename: Hongyang
authors.initials: H
authors.lastname: Tan
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D017711:Nonlinear Dynamics; D017084:Otoacoustic Emissions, Spontaneous; D010469:Perceptual Distortion; D010470:Perceptual Masking; D013018:Sound Spectrography; D055815:Young Adult