Recovery of distortion-product otoacoustic emissions after a 2-kHz monaural sound-exposure in humans: Effects on fine structures

Abstract

A better understanding of the vulnerability of the fine structures of distortion-product otoacoustic emissions (DPOAEs) after acoustic overexposure may improve the knowledge about DPOAE generation, cochlear damage, and lead to more efficient diagnostic tools. It is studied whether the DPOAE fine structures of 16 normal-hearing human subjects are systematically affected after a moderate monaural sound-exposure of 10 min to a 2-kHz tone normalized to an exposure level L(EX,8h) of 80 dBA. DPOAEs were measured before and in the following 70 min after the exposure. The experimental protocol allowed measurements with high time and frequency resolution in a 1/3-octave band centered at 3 kHz. On average, DPOAE levels were reduced approximately 5 dB in the entire measured frequency-range. Statistically significant differences in pre- and post-exposure DPOAE levels were observed up to 70 min after the end of the sound exposure. The results show that the effects on fine structures are highly individual and no systematic change was observed.

Safe Use of Acoustic Vestibular-Evoked Myogenic Potential Stimuli: Protocol and Patient-Specific Considerations

“…Consistent with Krause et al (2013), Stromberg et al (2016) did not find significant reduction in measurable hearing thresholds after exposure but found a reduction in DPOAE amplitude over a larger range of frequencies. Stromberg et al (2016) found a DPOAE reduction (2.1 dB) following cVEMP evaluation that was equivalent to half the reduction caused by exposure to the maximally allowed occupational noise for an 8-hr work day as reported by Reuter et al (2007) and Aranda de Toro et al (2010). Most recently, Mattingly et al (2015) report a case study of sudden permanent bilateral sensorineural hearing loss after cVEMP and oVEMP testing with stimulation intensities ranging between 128 and 135 dB pSPL.…”