A comparison of the nonlinear response of the ear to air and to bone-conducted sound

The nonlinear response of the ear to air-conducted sound has been studied to some depth. However, the nonlinear response of the ear to bone-conducted sound has received less attention. A comparison of the nonlinear response of humans to air and bone-conducted sound is presented. Two different human subject test techniques were combined in this investigation. The first was a psychoacoustic investigation measuring the perceived cancellation of a bone-conducted sound stimulus with another air-conducted sound stimulus. The measurement was accomplished through a loudness-matching technique. The second investigation used distortion product otoacoustic emissions (DPOAEs) to make objective measurements of the response of the ear to both air-conducted sound and bone-conducted sound. The results were compared to determine whether the measured compression effects were similar for the different types of stimuli. Results show that both the measured psychoacoustic response and the measured objective response of the ear to air-conducted sound and to bone-conducted sound were similar at 2 and 4 kHz.