Vibrotactile Display of Music on the Human Back

We present an experiment designed to reveal characteristics of a tactile display that presents vibrations representing music to the back of the body. Based on the model human cochlea, a sensory substitution system aimed at translating music into vibrations, we are investigating the use of larger contactor sizes (over 10 mm in diameter) as an effective device for the detection of signals originating from music. Using the method of limits, we measured ability to discriminate the frequency of vibrotactile stimuli across a wide range of frequencies common to western classical harmonic music. Vibrotactile stimuli were presented to artificially deafened participants using a large contactor applied to the back. Between 65 Hz (C2) and 1047 Hz (C6), frequency difference limens (FDL) were consistently less than 1/3 of an octave and as small as 200 cents. These findings suggest that vibrotactile information can be used to support the experience of music even in the absence of sound, and that voice coils are effective in presenting some characteristics of sound as vibrations.