Related Experiment Video
Updated: Mar 6, 2026
Simultaneous Transcranial Alternating Current Stimulation and Functional Magnetic Resonance Imaging
Published on: June 5, 2017
Modulation of auditory percepts by transcutaneous electrical stimulation
Margarete Anna Ueberfuhr1, Amalia Braun2, Lutz Wiegrebe3
1German Center for Vertigo and Balance Disorders, University Hospital Munich, Ludwig-Maximilians-Universität München, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Martinsried, Germany.
Transcutaneous electrical stimulation does not affect cochlear function, as measured by otoacoustic emissions. However, electrical stimulation impacts auditory perception and illusions, suggesting modulation of the retrocochlear auditory pathway.
Area of Science:
- Neuroscience
- Auditory System Research
- Vestibular System
Background:
- Galvanic vestibular stimulation (GVS) elicits vestibular reflexes via transcutaneous electrical stimulation.
- GVS is thought to primarily affect the vestibular periphery, but its precise mechanism (hair cells vs. afferents) is debated.
- The impact of electrical stimulation on the adjacent cochlea and auditory pathway is understudied.
Purpose of the Study:
- To investigate the effects of transcutaneous electrical stimulation on the human auditory periphery.
- To assess cochlear function using evoked and spontaneous otoacoustic emissions.
- To explore electrical stimulation's influence on the retrocochlear ascending auditory pathway via psychoacoustic measures.
Main Methods:
- Recorded distortion product otoacoustic emissions (DPOAEs) and spontaneous otoacoustic emissions (SOAEs) during alternating current electrical stimulation (2 Hz, 1-4 mA).
- Administered psychoacoustic tests, including pure tone perception and auditory illusions (Bounce tinnitus, Zwicker tone), during electrical stimulation (4 Hz, 2-3 mA).
- Compared otoacoustic emission and psychoacoustic results during electrical stimulation versus baseline conditions.
Main Results:
- No significant changes were observed in evoked or spontaneous otoacoustic emissions during electrical stimulation.
- The majority of participants reported significant perceived amplitude modulations in pure tone perception and auditory illusions.
- Psychoacoustic measures indicated that the retrocochlear ascending auditory pathway is modulated by electrical stimulation.
Conclusions:
- Transcutaneous electrical stimulation, at the tested currents, does not impair cochlear function as indicated by otoacoustic emissions.
- Electrical stimulation demonstrably affects auditory perception and illusions, pointing to modulation of the retrocochlear auditory pathway.
- This suggests GVS may have differential effects on the vestibular periphery and the central auditory system.
