Our hearing is a complex system involving both our ears and our brain. Hearing starts as sound waves that reach the eardrum and cause it to vibrate. This vibration travels though the ear canal and reaches the cochlea where it stimulates sensory hair cells. These send neural signals to the brain where it uses special auditory circuits to translate these signals into speech, bird calls, train whistles or what ever type of sound the brain recognizes.
Normal hearing develops from birth as our brain learns from our environment to recognize the different sounds we hear and to categorize them. The ear-brain system changes as we age and becomes less efficient. Typically some of the sensory hair cells become damaged or broken, particularly those involved in the higher frequencies. Recognizing and understanding speech depends heavily on these higher frequencies. Also, as we age, our brain circuits can become less efficient and it can take longer for the brain to process the incoming sound as it competes with our other mental resources. This can be why it may be more difficult to understand what people are saying even though you seem to be hearing the sounds. They are just not making complete sense.
Hearing aids are generally the solution, but you have to recognize that hearing aids, even the best ones available at present can only aid but not completely cure your hearing loss. This is because the hearing aids can only process and amplify the sound that you are hearing. They cannot correct the existing damage.
Our hearing losses are individual to each of us. There is no “one-size-fits-all” solution. This individuality depends greatly on how severe and what type of deterioration has occurred to the ear-brain system. When the hearing aids are introduced into the system, they pick up the sound waves and modify and amplify them before they reach the eardrum. These modified signals now change the way the brain responds. Under the best of circumstances this will cause significant improvement in a person’s speech recognition abilities. It is important to recognize, however, that while hearing aids modify and amplify the sounds we are hearing, there is still a period of adjustment that must take place in the brain. We are now hearing sounds differently, and just as we had to learn the sounds in our environment when we were growing up, we start a similar part of the process all over again. This is because the new hearing aids are delivering different sounds to the brain and even sounds we may not have been able to hear for some time. Speech will sound louder and even more clear but is not the same as you were hearing before the hearing aids. Sound frequencies that you weren’t hearing before are suddenly re-introduced. Perhaps turning on the tap now sounds to you like Niagara Falls, other high frequency sounds grate on your nerves or people sound like they are talking too loud. What is happening?
All the while over the years you were losing some of your hearing, your brain was making adjustments to minimize the loss. Brain circuits were being diverted from other tasks to help you hear as well as possible. The brain was turning up the volume of the weaker signals coming from the ear. This adjustment is a slow process and it takes time for the brain to respond properly. When you start to use hearing aids, the new, strong, signals from the hearing aids starts a process that will cause the brain brain to start to turn down the volume. It takes the average person at least 3 weeks to readjust to these new stronger signals. During this period of adjustment, the new sound delivered by your hearing aids will gradually begin to sound normal again. To help with this adjustment the best thing that you can do is to wear your new hearing aids continually. Put them in first thing in the morning and wear them all day. People who say “I tried my hearing aids and they sound too loud so I put them away in a drawer” are not giving their brain a chance to adjust. Hearing aids are not like eye glasses that you just put on and get instant correction. Remember that ear damage.
Hearing aids do not always work well for everybody. There is still much we cannot explain about the variance in hearing aid outcomes. The things that we can explain fall into two categories,
(1) user-centred variables such as age, attention, motivation and biology; and
(2) the versatility of the particular hearing aids being used and how well these hearing aids were adjusted for the individual’s hearing loss.
Some of the user centred variables, age and biology, have already been discussed. The importance of attention and motivation cannot be over-emphasized. They are the only factors the user can control. If you approach your use of hearing aids with a positive attitude and the expectation that you will succeed, the result will be much better than if you set yourself up for failure. If you persist and give your brain the time to adjust itself you should get good speech recognition back.
The hearing aid that you purchase and how they are adjusted by your hearing clinician for your particular needs is also very important. Modern hearing aids do much more than just amplify the sound waves that they receive. The speech recognition programs built into the hearing aids modify the sound waves in ways that adjust to your particular hearing loss. They change them in ways that help the brain respond positively to the sounds that they send to the eardrum. The role that the audiologist or practitioner plays in helping you hear better is crucial.
In summary, if you are planning on trying hearing aids to help you hear better, get your hearing aids early, before your ear-brain system has deteriorated too much.
- Find a good hearing professional and get a complete hearing test.
- Tell them as much as you can about how your hearing loss is affecting your and your lifestyle and what you would like to have changed.
- Try the hearing aids with the expectation that they will help you.
- Give your brain time to re-adjust to the new sounds and you are hearing.
- Go back regularly for fine-tuning until they are completely satisfactory to you.
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