Presentation of Low-Frequency Vibration to the Face Using Amplitude Modulation.

This study proposes a method to present pure low-frequency vibration sensations to the face that cannot be presented by small commercially available vibrators. The core innovation lies in utilizing an amplitude modulation technique with a carrier frequency of approximately 200 Hz. Due to the absence of Pacinian corpuscles in the facial region-receptors responsible for detecting high-frequency vibrations around 200 Hz-only the original low-frequency signal is perceived. Three experiments were conducted. Experiments 1 and 2 were performed on the forehead to confirm that the proposed amplitude modulation method could produce the desired low-frequency perception and to evaluate the subjective quality of the vibration. The results suggested that the proposed method could produce the perception of desired pure low-frequency vibration when applied to the forehead. In Experiment 3, the proposed method was applied to the whole face, and its range of applicability was explored. The results indicated that the original low-frequency vibration was clearly perceptible around the eyes, cheeks, and lower lip area.