Wednesday, September 26, 2012

The Way It's All Going To Go Down

 Allow me to introduce you to my friend, the Familiar Sounds Audiogram. This is a good illustration about how loud and soft life can be, and is also helpful for explaining the benefits of hearing aids versus cochlear implants.

The first thing you'll notice about the audiogram is that pinkish blotch near the top. This is commonly referred to as the "speech banana." In order to hear and reproduce speech, an individual must be able to hear within both this decible and frequency level. In order to over-simplify, decibles can be thought of as how loud or soft a sound is, and frequency is  how high or low a sound is.

The auditory-brainstem response test (ABR) is only able to test sounds up to a certain decible level, usually around 90 to 100 dBs. This is why both Gianna and Pia's ABR's were blank, they MIGHT be able to hear very, very loud sounds (like an airplane or jackhammer if they were very close to those things) but we are not sure. The first step in seeing the full extent of the hearing loss is to use hearing aids and put the kids in a sound booth to do a behavioral test. Sounds are played and any responses to the sounds are rewarded with a visual cue.

For Gianna, and likely Pia as well, hearing aids did not show much benefit. I think I remember Gianna's aided audiogram said that she could hear somewhere in the 70-80 dB range. Not near enough sound to perceive and learn speech. When Pia is around 6 months old we will be able to put her in the sound booth and get a better idea of how much residual hearing she has, but the fact that her ABR was non-responive, it is highly unlikely hearing aids will allow her to speak and listen.

This brings me to the difference between a hearing aid and a cochlear implant, beyond the obvious difference that one is surgically implanted and the other is not. A hearing aid amplifies sound. A cochlear implant functions like a bionic ear.

So, sound enters through the external processor (worn behind the ear..."BTE") and is somehow converted to digital information. Don't ask me how because I have no clue. The sound jumps the magnet into the implant and travels down into the electrode array that is inserted into the cochlea. Normally, the hair cells in the cochlea stimulate the auditory nerve, but for Gianna, her hair cells do not work or are not present. With the implant, those electrodes act as hair cells to stimulate the auditory nerve, which then carries the information to the brain. A typical cochlea has thousands of hair cells; Gianna (and Pia eventually) will have 24 electrodes to stand in for those hair cells. This is why things like music sound very different to a cochlear implant recipient.

Following surgery and a recovery period of about two weeks, recipients have their devices activated for the first time. Then comes the work. There's speech therapy to help with speech production, aural rehabilitation (teaching the child what sound is and that it has meaning), auditory training to learn how to use the implants to listen, building auditory memory, and frequent visits to the audiologist for MAPings (the term for programming a cochlear implant to the specifications and needs of its user.) MAPs can be rough's voice sounded one way, but one tweak of the computer can make it sound another.

If you are still with me through all the explaining, here is the pay-off

I love that Gianna has outed all our recent TV due to the presence-of-a-newborn extravaganza we're currently working here. Anyways, the FDA requires a minimum of three months with hearing aids to show all other means have been attempted before proceeding with the invasive cochlear implant surgery. As mentioned, we will go at 6 months to get a new audiogram and begin documenting officially whether they are beneficial to Pia or not.

In the meantime we'll be back every few weeks to the audiologist to get new ear molds because Pia's ears will be growing so quickly. Additionally, I'm hoping some sound is getting to her in order to keep her auditory nerve nice and strong as well as keeping activation day from being extremely upsetting for her.

THE BIG FAT DISCLAIMER: I'm not an audiologist, otolaryngologist, speech pathologist, or speech therapist. I just have two Deaf kids. Each child has varying outcomes with cochlear implants due to factors such as health of the auditory nerve, shape of the cochlea, age of implantation, type of therapies received, and cognitive abilities.

It might seem like we know what we're doing, but we're mostly just making it up as we go along, cuz that's how we roll.


  1. well, for a non expert, you know your stuff!

  2. This post was so interesting and the video is too cute ;).

  3. SUCH an eldest G is!!!

    At the orchard the other day, I saw an elder sister who was trying to get her younger sister to take off her ears, so she could "borrow" them.