How to remove frequencies from a cochlear implant to improve spatial hearing

What is it about?

Hearing with two ears when you have bionic auditory protheses called cochlear implants (like for bilateral and single-sided-deafness CI users) can give you two types of advantages when understanding speech in the difficult situation of background noise and sounds. Advantage #1: the brain can use perceived spatial locations of sound (unfortunately, this does not work well with CIs and we want to improve it). Advantage #2: the head can block sound at an ear, more at high frequencies than low frequencies. We found how much you could adjust the frequency programming in one ear, given that the head blocks sounds at high frequencies more than low frequencies (from Advantage #2), so that we could improve spatial hearing (from Advantage #1). You can change things a lot (removing up to nearly 1000 Hz) and not lose the sound blocking advantages (from #2). And then we may be able to improve things even more (from #1).

Featured Image

Photo by Priscilla Du Preez on Unsplash

Photo by Priscilla Du Preez on Unsplash

Why is it important?

This tells us how to program a cochlear implant because the head does not block low frequencies. Since both ears will receive those low frequencies, you can remove them from the cochlear implant. This is very important for people who have cochlear implants with shallow insertions. Audiologists could use this information to maximize spatial hearing with these devices.