Vibratory Sensation Induced by Low-Frequency Noise: The Threshold for “Vibration Perceived in the Head” in Normal-Hearing Subjects

Our previous study, in which we measured the threshold levels for vibratory sensation induced by low-frequency noise under the condition that the subjects were allowed to perceive vibration in any part of the body, showed that the head was very sensitive to the vibratory sensation. In the present study, in which the head was designated as the body part that would perceive the vibration, we measured the threshold levels for experiencing “vibration perceived in the head” within the 16- to 80-Hz frequency range. The threshold levels for “vibration perceived in the head” were found to be very similar to the threshold levels measured in our previous study, which indicated the superior sensitivity of the head to vibratory sensation induced by low-frequency noise. A gap appeared around 40–50 Hz in the threshold level contour for “vibration perceived in the head”. In addition, the threshold levels for “vibration perceived in the head” increased when a subject wore an active noise cancelling earmuff. These results suggested the possibility that experiencing “vibration perceived in the head” was related to the pressure change in the ear.