Using tactile stimulation to improve speech-in-noise performance in cochlear implant users

Many cochlear implant (CI) users achieve excellent speech understanding in quiet listening conditions, but most perform poorly in the presence of background noise. An important contributor to this poor speech-in-noise performance is the limited transmission of low-frequency sound information through CIs. Recent work has suggested that tactile presentation of this low-frequency sound information could be used to improve speech-in-noise performance for CI users. The primary aim of the current study was to test whether tactile stimulation could enhance speech-in-noise performance in CI users using (1) a tactile signal derived from the speech-in-noise using an algorithm that could be applied in real-time, (2) a stimulation site appropriate for a real world application, and (3) a vibration signal that could readily be produced by a compact, portable device. Our previous work has suggested that training may be important in maximizing the benefit of tactile stimulation, so a secondary aim of this study was to establish the effectiveness of a short training regime. We measured speech intelligibility in multi-talker noise with and without vibro-tactile stimulation of the wrist in CI users. These measurements were made before and after training, which involved 20 minutes of exposure to speech-in-noise with concurrent tactile stimulation. Early results suggest tactile stimulation may improve speech-in-noise performance after training, and that training is important in establishing this improvement. If the approach used in this study is found to be effective, then it could offer an inexpensive and non-invasive means of improving speech-in-noise performance in CI users