Raghav Katyal, Jim Saroj Winston
Simulated conductive hearing loss significantly affects air-conducted masseteric vestibular evoked myogenic potential responses, often rendering them absent or diminished. However, bone-conducted responses remain robust and reliable in normal and simulated conductive hearing loss conditions, highlighting their diagnostic value when conductive pathologies compromise air-conducted responses.
INTRODUCTION: Masseteric vestibular evoked myogenic potentials assess saccular-masseteric pathway function using air-conducted or bone-conducted stimuli.
OBJECTIVE: This study investigated whether simulated bilateral conductive hearing loss differentially affects mVEMP response characteristics under air- and bone-conducted stimulation in young adults.
METHODS: Fifty healthy participants were included in the study. Conductive hearing loss was simulated in 25 individuals using silicone-blocked foam ear tips to create controlled bilateral attenuation. Masseteric vestibular evoked myogenic potentials were elicited using 500 Hz tone bursts delivered to the right ear through air and bone-conducted methods. Responses were recorded using a two-channel zygomatic electrode placement and analyzed for P1 and N1 latencies and P1-N1 peak-to-peak amplitude.
RESULTS: In the simulated conductive hearing loss group, air-conducted masseteric vestibular evoked myogenic potential responses showed decreased response rate, delayed latency, and reduced amplitude compared with normal hearing participants. In contrast, bone-conducted masseteric vestibular evoked myogenic potentials were consistently recorded in both groups, demonstrating significantly higher amplitudes and earlier latencies than air-conducted responses in the simulated conductive hearing loss group. Spectral analysis revealed a consistent peak around 100 Hz for all conditions except air-conducted stimulation in the simulated conductive hearing loss group, which showed no distinct peak.
CONCLUSION: Simulated conductive hearing loss significantly affects air-conducted masseteric vestibular evoked myogenic potential responses, often rendering them absent or diminished. However, bone-conducted responses remain robust and reliable in normal and simulated conductive hearing loss conditions, highlighting their diagnostic value when conductive pathologies compromise air-conducted responses.