Kudos to Hearing Review for catching this awesome video of a TED conference talk on why cochlear implant users can’t hear music well. This one hits home for me, because when I lost most of my hearing nine years ago, music suddenly became a discordant jumble of noise that was impossible to enjoy any more. Now I find it’s exactly what cochlear implantees experience.
Dr. Charles Limb describes how devastating the loss of music can be to his cochlear implant patients while explaining in layman’s terms why it happens. As both a musician and a cochlear implant surgeon, he combines his two passions to study the way the brain creates and perceives music. He is an Associate Professor, Otolaryngology, Head & Neck Surgery, at Johns Hopkins who performs cochlear implantations on patients who have lost their hearing. He is also an accomplished musician on the faculty of the Peabody Conservatory of Music who plays sax, piano and bass.
If you listen to the comparison on the video between “normal” symphonic music and an estimation of what people with cochlear implants hear, you will understand the problem better. Cochlear implantees can’t hear the difference–both sound equally bad (I can’t hear the difference either).
Part of the problem is that neither cochlear implants nor hearing aids are optimized as much for music as for speech. The chart that Dr. Limb displays shows the frequencies and sound levels you need to replicate or amplify for speech, versus the much wider range of frequencies required to convey the richness of music.
But the problem also extends to the brain’s ability to process sound as both music and speech, including the emotional impact music can have. Dr. Limb is fascinated with the idea “that acoustic vibrations in the air can make you feel deep emotion, something that can affect your life.” Music requires a comprehension of pitch, tone and timbre, but cochlear implantees, and people like me with certain kinds of hearing damage, can’t discern warmth in a tone or the timbre of a violin versus a trumpet–qualities that enable music to stir powerful emotions.
The interaction between the mechanical hearing functions and how the brain processes sound and music still is not very well understood. Sound waves are shaped within the ear canal and transmitted through the ear drum and middle-ear bones to the hearing-hair-cell nerves in the cochlea, where they are transformed into electrical impulses carried by the auditory nerve. But then the brain takes over and interprets those sound waves, understanding them as speech, music, a baby’s chatter or cry, random noise or other sounds.
Readers of Musicophilia by Oliver Sacks will be familiar with the mysteries of how the brain processes sound. I found some comfort in the research the book reviewed on the brain’s amazing ability to rewire itself to improve its comprehension of audio inputs after the hearing organs have been damaged. In one of his case histories (and to a lesser degree in my own experience), the brain is able to improve its comprehension of speech over time, and to a lesser extent music as well–to fill in the gaps when the hearing organs are malfunctioning.
But as Dr. Limb makes clear, a lot more is unknown than known at this point. How the brain processes and discerns the quality of music — pitch, tone and timbre — is relatively new territory for researchers. While cochlear implants (and hearing aids) have been wildly successful in restoring the ability of the deaf to hear and understand speech, there’s still a long way to go before they can restore a complete ability to appreciate music.
“If you had a sense to lose, we are furthest along medically and surgically with hearing,” says Dr. Limb, but he adds, “Most implant users really struggle and dislike music because it sounds so bad. So when it comes to this idea of restoring beauty to somebody’s life, we have a long way to go.”
Nam tran says
I’m cochlear implant 7 months ago and suddenly I can not hear myself tsk and can’t hear other person on my iPhone even with processed on.
bestvideocamera2015.com says
We are a bunch of volunteers and opening a new scheme in our community.
Your web site provided us with valuable info to work
on. You have done a formidable activity and our whole group will be grateful to you.
Lori Mertes says
I am a cochlear implantee who enjoys music now more than ever. I can hear the different instruments and can identify them too. I am not sure what the Dr. is saying when he says I won’t be able to really appreciate music again. I can and do. I also find music very soothing as compared to talking and listening to TV.