Temporal modulation perception of bone-conducted ultrasound
Takuya Hotehama, Seiji Nakagawa
Ultrasonic vibration generates a sensation of sound via bone-conduction. This phenomenon is called bone-conducted ultrasonic (BCU) hearing. In order to clarify perceptive characteristics of temporal modulation for BCU, the influence of modulation frequency on the sensitivity for detecting amplitude modulation of sinusoidal carriers 10, 20 and 30 kHz was examined. Temporal modulation transfer functions (TMTFs) obtained at each carrier frequency suggest that the auditory system has an ability to process timing information in the envelopes of amplitude modulated BCUs at lower modulation frequencies, as is the case with audible sounds. At higher frequencies, the possible contributions of peripheral filtering on the shape of the TMTF were examined.
Key words: bone-conducted ultrasound, amplitude modulation, temporal modulation transfer function