Abstract
BACKGROUND: High levels of sound intensity can be detected by the vestibular system. It is a clinical method used to assess the vestibular system’s response to sound stimulation. In healthy individuals, research has indicated that the use of low-frequency stimuli results in decreased vestibular evoked myogenic potential (VEMP) thresholds, especially a 500 Hz tone-burst. As people age, their frequency tuning changes, moving towards higher frequencies. METHODS: Eighty healthy participants participated in this cross-sectional investigation. Both air conduction (AC) and bone conduction (BC) were used as stimulation methods in the ocular VEMP (oVEMP) test. The following oVEMP parameters were assessed in the study: the inter-frequency peak amplitude ratio (FAR). Furthermore, a rectified FAR (Frequency Amplitude Ratio)—a technique that normalizes the VEMP response amplitude according to the strength of muscle contraction as determined by EMG (Electromyogram) —was examined. RESULTS: Statistically significant differences in FAR and rFAR (rectified Frequency Amplitude Ratio) of oVEMP were observed among the 5 age groups when using both AC and BC stimuli. CONCLUSION: This study used both AC and BC stimuli to determine age norms for the FAR (1000/500 Hz) of oVEMP. When compared to younger age groups, participants over 50 had much greater FAR and corrected FAR values. Comparable FAR results were obtained from both AC and BC stimuli, suggesting that either approach can be utilized for testing.