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

2025-08-01

AI Summary

This study addresses the challenge of delivering pure low-frequency vibrotactile perception directly to the face using off-the-shelf miniature vibrators, which typically lack sufficient low-frequency output. Leveraging the physiological insensitivity of facial Pacinian corpuscles to high-frequency stimuli, we propose an amplitude modulation (AM)-based indirect low-frequency perception method: a 200-Hz carrier wave is modulated with target low-frequency envelopes, and the skin’s nonlinear mechanoreceptive response enables perceptual demodulation of the intended low-frequency component. Through systematic psychophysical experiments across the forehead, periorbital region, cheeks, and lower lip, we validate the method’s efficacy. Results demonstrate, for the first time, clear and discriminable low-frequency vibrotactile perception across the entire face using only commercially available actuators—without custom hardware—achieving optimal performance on the forehead. This work establishes a low-cost, hardware-compatible paradigm for low-frequency haptic encoding in wearable tactile interfaces.

Technology Category

• Computer Vision: Low Level & Physics-based Vision
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Cognitive Modeling & Cognitive Systems: Affective Computing

Application Category

• Economics, Online Markets and Human Computation: The sharing economy
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods

Abstract

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.

Problem

• Present low-frequency vibrations to the face using amplitude modulation
• Overcome limitations of small vibrators for facial vibration perception
• Verify perception quality and applicability on different facial areas

Innovation

• Amplitude modulation for low-frequency facial vibration
• 200 Hz carrier frequency bypasses facial receptors
• Effective on forehead, eyes, cheeks, and lips