As I write this post to all you lovely Earpluggers, I must warn you. I am sitting in my little computer nook in my dining room where I am currently overlooking the most temperamental sunset I have ever seen. The sky itself is a pale blue, but the clouds are a sort of ominous gray lined in a pinky golden fluff. The sun is peeking over the tops of the clouds and seems positively determined to pelt all of its remaining sunlight straight on my corneas. So, friends. You will excuse me if I have any typos today. I am writing this blindly.
Much has come to pass since I last checked in. I have two weeks of my internships under my belt. I visited some amazing friends up in UC Davis (check out my guest post on the Cochlear Wire blog about traveling http://thewire.cochlearamericas.com/shayna-shares-tips-and-stories-for-the-holidays/). I finished a season and a half of Once Upon a Time on Netflix. Most importantly, I ate a s’more in the spirit of summer.
In the midst of my crazy daily life, one thing has truly captivated me this month. That thing is music. All right, all right. It isn’t much of a surprise considering that one of my internships revolves around music and music therapy. Yet, because of my internship I have been reflecting on my musical experience and how my exact perception of music comes to fruition in my implant.
Here’s the thing: there are two ways to stimulate pitch in a person’s ear. I want you to imagine a cochlea. Or don’t, there is a picture right here.
Now, let’s pretend to be a sound signal. Lift your finger and tap somewhere on the cochlea. Imagine that your finger is stimulating a hair follicle on the cochlea that sends information to the brain about how that signal should sound as a direct result of the location where you tapped the cochlea. That is called spatial processing. It is what happens when a signal is picked up at a specific location on the cochlea that results in a specific pitch.
Okay, so perhaps that wasn’t rocket science. Hold on, now, what I am about to say may seem less straightforward. Pitch perception does not soley rely on the spatial processing of sound signals. It can also rely on temporal processing, that is, the rate of stimulation at any given location on the cochlea can transmit sounds of different pitch. This can occur even at the same location! So, let’s go back to our little activity. If you tap slowly at any spot on the cochlea you will transmit one sound. If you tap faster on the same spot, the frequency of sound (i.e. pitch) will change!
“Regular” hearing seems to be taking advantage of both types of processing, however, cochlear implants do not. Cochlear implants are made solely for speech perception, and it does an excellent job of that. The cochlear implant’s abilities encompass the vast majority, if not all, of the speech frequencies and pitches. What the cochlear implant does not do, however, is restore perfect hearing. Speech isn’t the only thing worth restoring to the deaf. How about music, for instance? The frequencies and melodies that embody music can lie within the speech frequency range (the speech “banana”) but a lot of auditory information that does not fall in that specific region is lost. Thus, when orchestral music is played to a cochlear implant recipient, it is not as nuanced and beautiful as it may sound to you. There is definitely a lovely quality to orchestral music in my opinion, but it is more apt to sound like noise in my case or in other CI recipients’ cases.
Why does this happen? No one is quite sure, and multiple studies are being done to uncover this question. However, one solution researchers have put forth is that the cochlear implant seems to focus more heavily on spatial processing because that is all that is really needed to cover speech. Temporal processing, if integrated with spatial processing, may restore or permit CI recipients to hear music the way “normal” hearing people do. This is much more easily said than done. As anyone who owns any technological device knows, it ain’t easy getting a machine to do what you want it to. In this case, more knowledge of these concepts, a ton of coding, and gobs of money are needed to accomplish this goal.
As a pre lingually deaf cochlear implant recipient, I often wonder what this reduced frequency range of my cochlear implant does to interfere with my musical experience. I adore music: dancing to it, creating it, and simply listening to it. This was certainly not the case before my implant. I did love to dance and I did play several instruments, but I think my joy deepened as a result of the implant. Could my joy be expanded more? Am I being “robbed” of the “true” musical experience? Does not having full access to all the frequencies alter my ability to enjoy the music/does it change what I hear? Can I miss an experience I never had to begin with? Is music listening/loving a relative experience? What is the meaning of life?
I have spent many hours listening closely to songs on the radio, I have dusted off my out of tune piano, and I have strummed multiple guitars, straining my ears and struggling to wrap my mind (ears?) around this phenomenon.
I watched this awesome TED Talk on the topic: http://www.ted.com/talks/charles_limb_building_the_musical_muscle#t-57204
You know what guys? I have absolutely no idea how I feel about it. To be honest, I start getting too wrapped up in the music to even remember that I am supposed to analyzing my experience. If and when cochlear implants are designed to portray the entirety of the musical spectrum, I know I will be in line to get one is less than an eight count.
‘Til then, baby steps, people. Baby steps.