Assessing Cortical Modulation of Cochlear Function with Transcranial Magnetic Stimulation

Repetitive transcranial magnetic stimulation (rTMS) is widely investigated as a non-invasive neuromodulation technique; however, its capacity to modulate cortical excitability within the auditory system remains poorly understood. This study examined whether rTMS applied to auditory cortex regions influences peripheral auditory structures via top-down cortical feedback. Electrophysiological markers of auditory and neural function were assessed in 19 normal-hearing participants before and after stimulation. No significant changes were observed in either peripheral or central auditory responses, suggesting that the rTMS protocol employed here did not produce measurable alterations in auditory cortical excitability, despite being based on current conventions in both research and clinical practice. These findings highlight the need for refined stimulation parameters and standardised guidelines to improve the efficacy and reproducibility of rTMS in auditory neuroscience. Data collection took place in 2023 at the Australian Hearing Hub (Level 1 sound-treated and electrically shielded booths), Sydney, Australia. This study primarily focused on physiological responses to sound, with participants undergoing rTMS designed to modulate auditory processing. Ethical approval was granted by the Macquarie University Human Research Ethics Committee (ref: 52023333448210). All participants provided written informed consent and received a small financial reimbursement for their time.