I was very excited when I first heard of the project involving Marissa. I couldn't wait to have the hearing test done, fit her with the hearing aids and start the process.
However, the results of the hearing test, I have to be honest, had me a bit worried. Her audiogram indicated that she has a profound hearing loss in both ears. She hasn't really worn hearing aids all her life, and since she has had the hearing loss from 18 months of age, it meant that her auditory nerve hasn't had a lot of stimulation. This could count against her, as we know that the hearing nerve loses some of its function if not stimulated continuously (it's called sensory deprivation). Let me give you an example of what I have seen in private practise to demonstrate the effect this has on the prognosis with a hearing aid:
The brain and its ability to decode sound
Sometimes people with hearing loss wait much too long before they seek help in the form of hearing aids. If they put it off long enough, the hearing nerve and brain will start to lose its ability to "decode" what it has heard. This has the most profound effect on speech, since speech is a very complex signal, comprising of quick changes in frequency as well as intensity (volume), with the added "burden" of understanding or interpreting the message portrayed by all these speech sounds.
Speech recognition the real test
It makes sense then, that this effect will be seen best in auditory tests where speech recognition is done. I have seen this many a times in cases where the patient had hearing loss in both ears, but chose to wear a hearing aid on one ear only. As they come back over the years for follow-up tests, the deterioration can be best seen in the speech discrimination scores of the ear that has not been fitted with a hearing aid. The deterioration is normally not as significant in the pure tone tests, but can be quite devastating in speech recognition.
How is this test done?
The speech discrimination test is done in the following way: short, phonetically balanced words are read to the patient at different intensity levels. The aim of the test is to find the intensity at which the patient can hear the words 100% correctly. There are no visual clues and the patient has to rely on what they hear only.
What do the results mean?
The speech discrimination scores in a patient who experiences sensory deprivation will reflect the following: during the test, they will report that they can hear the voice talking, but that they struggle to make out what has been said. Even with increased volume, they never seem to reach 100%, and will sometimes even hear worse when the intensity is increased.
I have seen cases where the patient could only hear 20% of the words correctly at a given intensity level, and 0% at the intensity level just below and just above. The prognosis with a hearing aid in such cases is not good, as the hearing aid will not be able to make him hear better than the 20% he has achieved during the test. The hearing aid will still help him a lot, and less complex sounds, such as environmental sounds, etc., will still be improved with the hearing aid, as will be his ability to hear speech, but in this case the effect of even the best hearing aid on the market would be limited by the sensory deprivation that has taken place in the ear.
Marissa performed poorly in the speech discrimination test – she was not able to repeat the words correctly with visual clues at the maximum output of the audiometer. Also, the last time she tried hearing aids were over three years ago, and it wasn't a good experience for her. She reported that the sounds were very loud, uncomfortable, and gave her headaches, so she ended up discarding the hearing aid. From what I understand, the last time she really wore hearing aids, was in primary school.
So now you understand my initial concerns regarding fitting Marissa with hearing aids. I had no doubt in my mind that she would benefit from our hearing aids, but I was worried about the fact that she most probably would only have limited benefit as result of the profoundness of her hearing loss, the sensory deprivation and the lack of ability to hear speech at amplified levels. Also, Marissa doesn't talk a lot, and mainly uses gestures to communicate. Nonetheless, I have always been promoting the fact that it is always worth the try, even if it looks like it is against all odds.
So far, we have all been pleasantly surprised by her performance and she is doing much better than we anticipated. It has to be said that her strong will and determination to make a success of it, also plays a huge role and it is a wonderful experience to work with such a motivated person. She has already proven in many other areas in her life, that she is a go-getter, and that she refuses to be limited by other people's perceptions, and I think her experience with her new, digital hearing aids will be no exception.
I get the impression that she really tried on previous occasions to get used to hearing aids, but that the limitation in the technology she tried out, just made it incredibly difficult to persist (she complained of headaches when using it, etc). It is good to see, once again, that the advancements Widex has made in their break-through digital philosophy, has the desired impact, when applied to everyday life. It is also good to see how our product gave her the opportunity to get back into a hearing world in a comfortable, easy way. Widex has always advocated natural, comfortable sound and through our hearing aids we try to make the transition back into a noisy world as easy, comfortable and enjoyable as possible.
Marissa has already reported on a number of phenomenal experiences, which I will share with you shortly. The whole process so far has also allowed me to have a glimpse into the world of a hearing impaired person, and I have realised, once again, how many things we take for granted in a hearing world. Many of the stories Marissa reported back, have actually brought a lump to my throat.
Marisa's new sound experiences
She has become aware of many different sounds, like the sound of rice cooking on the stove, the sound of the rain on the roof, etc.. She was very surprised to hear that a fly actually makes a sound! When I spoke to her mom on the phone this morning, she had another interesting story to tell: Marissa wasn't aware of the fact that voices could be used to convey emotion, as she has told her mom that she has become aware of that! She mentioned that swearwords are normally spoken quite loudly!