Journal of the American Academy of Audiology · 2003 · 89 citations · 19 references
Health ProfessionsAudiologyNeuroscienceHearing ScienceSensory NeuroscienceSensory PhysiologyAuditory NeuropathyAuditory NeurophysiologyAuditory PhysiologyHearing ImpairmentHearing LossOtoacoustic EmissionsAuditory Nerve DysfunctionAuditory Neuropathy AssessmentAuditory Neuropathy Spectrum Disorder PathophysiologyBilateral Auditory Neuropathy Spectrum DisorderCentral Auditory Nervous System FunctionOlivocochlear SystemSuppressionUnilateral Auditory Neuropathy Spectrum Disorder
The study evaluates olivocochlear reflex function by measuring transient evoked otoacoustic emission suppression in nine patients with bilateral auditory neuropathy/dys‑synchrony versus normal controls. TEOAEs were recorded with 65‑dB clicks, with and without broadband noise presented binaurally, ipsilaterally, or contralaterally in a forward‑masking paradigm, and suppression characteristics were also examined in a unilateral case. Patients exhibited markedly reduced suppression (<0.22 dB) compared to controls (4.47, 2.41, 1.52 dB), indicating impaired efferent responses linked to afferent deficits and supporting the use of efferent suppression as a differential diagnostic tool.
Function of the olivocochlear reflex, measured by suppression of transient evoked otoacoustic emissions, is assessed in nine patients with bilateral auditory neuropathy/dys-synchrony and compared to matched control subjects with normal auditory function. TEOAEs were acquired using 65 dB peak sound pressure linear clicks with and without the presence of broad-band noise presented binaurally, ipsilaterally, or contralaterally in a forward masking paradigm. Efferent suppression differed significantly between subject groups (p < .0001). Mean suppression was less than 0.22 dB across all suppressor noise conditions for the auditory neuropathy/dys-synchrony subjects. TEOAE suppression averaged 4.47 (binaural), 2.41 (ipsilateral), and 1.52 (contralateral) dB in the control subjects. Suppression characteristics across the three suppressor conditions were also assessed in one patient with unilateral auditory neuropathy/dys-synchrony. The results suggest that poor efferent responses are related to compromised afferent input to the OCR pathway and support the use of efferent suppression of otoacoustic emissions as a differential measure of auditory function in patients with auditory neuropathy/dys-synchrony.
19
Efferent innervation of the organ of corti: two separate systems
W. Bruce Warr, John J. Guinan · Brain Research · 1979 · 632 citations