Measurement of vibrotactile thresholds on the fingertip to assess vibrotactile presentation of musical notes to people with and without a hearing impairment

摘要

This paper describes measurements of vibrotactile detection thresholds on the distal phalanx of the middle finger for musically relevant sinusoid frequencies, namely musical notes C and G in the range C1 to C6. The purpose is to inform research on the use of vibrotactile information by musicians with hearing impairments in order to facilitate group performance. Analysis of thirty-one participants with normal hearing and eight participants with a hearing impairment showed no statistically significant difference between detection thresholds in these two groups, regardless of whether linear displacement or displacement in decibels was used. To define the available dynamic range, the maximum vibration level that could safely be used for performance/practice was set using frequency-weighted acceleration. A post-hoc experiment was carried out to assess whether participants with normal hearing felt the onset and/or sustain of notes with a 1s duration when presented at threshold and 10dB above threshold. Results show that onset awareness increases over the pitch range G4 to C6, being particularly evident from A5 upwards in this experiment. This has implications for the perception of music using vibration because detecting only the onset of a note will not give sufficient information to identify the note itself.