Audio-tactile association improves pitch perception in listeners with and without cochlear implants

Auditory perception can improve when accompanied by somatosensory information, with beneficial effects for hard-of-hearing individuals. Further enhancement could occur by mapping discrete musical pitch information onto tactile spatial patterns across four fingertips. Unlike previous studies, we used tactile stimuli that marked only the sound onsets via light pressure from air-inflated plastic membranes. Pre- and post-learning pitch discrimination tests used vocoded-audio only, vocoded-audio with tactile, and tactile-only conditions. The learning phase was a 10-minute nursery song melody listening task with the audio-tactile condition. In Exp. 1, normal-hearing listeners heard melodies in the original audio; in Exp. 2, normal-hearing listeners heard melodies with vocoded-audio; and cochlear implant (CI) users listened to the original audio. All groups performed best in the audio-tactile condition before the learning phase, and these immediate benefits were maximal at intermediate pitch intervals. Furthermore, CI users showed greater improvement in the audio-only condition after exposure, indicating the rapid transfer effect.