Enhancing spatial hearing in cochlear implant users using vibrations on the wrists

Fletcher, Mark, Cunningham, Robyn, Zgheib, Jana, Verschuur, Carl and Perry, Samuel W (2020) Enhancing spatial hearing in cochlear implant users using vibrations on the wrists. In British Cochlear Implant Group Meeting 2020: Improving Hearing Healthcare in the 21st Century.

Abstract

Aim: Many cochlear implant (CI) users struggle to locate and separate sounds that come from different locations, particularly the majority of CI users in the UK who are implanted in only one ear [1]. Recently, it has been shown that speech-in-noise performance in CI users can be improved by augmenting the electrical signal from the implant with a haptic signal that provides missing sound information (“electro-haptic stimulation” [2]). We aim to test whether haptic stimulation on the wrists can be used to improve spatial hearing in CI users.
Method: We measured localization ability in 12 unilaterally implanted CI users, either only with audio, or with combined audio and haptic stimulation. All conditions were measured before and after a short training regime (lasting around 50 minutes). We derived our haptic signal from the audio that would be received by CI or hearing aid microphones behind each ear. The signal from each ear was then remapped to a frequency range where the skin is most sensitive to vibration and delivered to each wrist. This meant that the intensity difference between the wrists corresponded to the intensity difference between the ears, which is a key spatial hearing cue.
Results: We found that auditory localisation accuracy improved substantially when audio and haptic stimulation were provided together (electro-haptic stimulation). After a short training regime, participants’ average RMS error with electro-haptic stimulation was reduced to just 22.7°, which is comparable to the performance of bilateral hearing aid users (~19°) [3,5]. Even with no training, adding haptic stimulation reduced the RMS error from 47.2° to 29.3° on average. This performance is similar to the average performance achieved by CI users with implants in both ears (~27°) [3,4], or users with a CI in one ear and healthy hearing in the other (~28°) [3].
Conclusions: Our approach was designed to be easily transferable to a real-world application. The haptic signal was processed using a computationally lightweight algorithm that could be applied in real-time and was delivered at a vibration intensity that could readily be achieved by a low-cost wearable device. This could have an important clinical impact, providing an inexpensive, non-invasive means to dramatically improve spatial hearing in CI users.

This record has no associated files available for download.

Contributors

Download statistics