Affiliations: [a] Department of Otolaryngology-Head and Neck Surgery and Audiology, Mayo Clinic, Scottsdale, AZ, USA | [b] Division of Preventive, Occupational and Aerospace Medicine, Mayo Clinic, Scottsdale, AZ, USA | [c] Department of Neurology, Mayo Clinic, Scottsdale, AZ, USA | [d] IST Biomedical, Infoscitex Corporation, Waltham, MA, USA | [e] Department of Otorhinolaryngology-Head and Neck Surgery and Audiology, Mayo Clinic, Jacksonville, FL, USA
Correspondence:
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Corresponding author: Michael J. Cevette, PhD, Department of Otolaryngology-Head and Neck Surgery and Audiology, Aerospace Medicine and Vestibular Research Laboratory (AMVRL), Mayo Clinic, 13400 E Shea Blvd, Scottsdale, AZ 85259, USA. E-mail: mcevette@mayo.edu
Abstract: Galvanic stimulation has long been used as a nonmechanical means of activating the vestibular apparatus through direct action on the vestibular nerve endings. This stimulation has been reported to be safe, but no studies have examined the potential changes in the corresponding cochlear receptors. The aim of the present study was to evaluate the effect of galvanic vestibular stimulation (GVS) on distortion product otoacoustic emissions (DPOAEs). Fourteen subjects underwent DPOAEs during several conditions of GVS. The DPOAEs ranged from ∼ 1 kHz to ∼ 8 kHz at 65/55 dB for f1/f2 and with an f2/f1 ratio of 1.2. The subjects were evaluated at 10 stimulation conditions that ranged from −2.0 mA to +2.0 mA for each frequency. Statistical analysis showed no significant differences in DPOAE amplitudes for all conditions with and without GVS. Results also showed no significant differences between DPOAE amplitudes before and after GVS. Multivariate analysis found subject variability in DPOAE amplitude, which was not thought to be GVS related. Results indicated that GVS produced neither temporary nor permanent changes in DPOAEs.
