Comparisons of air and bone conduction transfer properties utilizing stimulus frequency otoacoustic emissions

Otoacoustic emissions represent cochlear responses to auditory stimuli, enabling the investigation of air conduction (AC) and bone conduction (BC) transmission. This study developed and validated a non-invasive, objective method for measuring the sensitivity difference between AC and BC transmission, here termed bone-air difference transfer property (BADTP), using stimulus frequency otoacoustic emission (SFOAE). The BADTP was defined as the difference between the AC transfer property and the BC transfer property. To cross-validate the objective approach, BADTP was compared with subjectively obtained hearing thresholds. Measurements were conducted across frequencies from 1000 to 4000 Hz in ten individuals with normal hearing. Results revealed that the mean differences between the two methods were within 2 dB at frequencies from 1000 to 1600 Hz, while both methods showed similar trends from 1850 to 4000 Hz. The proposed SFOAE-based method for measuring provides valuable insight into BC transmission, with potential applications for objective assessment of BC function in research settings.