Components of your successful hearing aid fitting
We work out how much sound you need to hear well with your hearing aids by putting your audiogram (hearing test results) into the hearing aids software. The software calculates the amount of sound you need at each frequency and loudness level. Usually, hearing aids amplify quiet sound more than loud sounds to make soft sound audible and keep loud sounds at a comfortable level. Each hearing aid manufacturer has there own rationale (or amplification philosophy) of how they choose to amplify sound. This is a good starting point for getting the sound right in your hearing aids; but the next two steps are essential for a successful hearing aid fitting.
Adaptation time is a term to describe the time it takes to adjust to hearing sound again. It is normal to hear the way you do; if you have normal hearing, this is normal for you. If you have hearing loss, your current hearing level is normal for you too.
When you have had hearing loss for a long time, it is a surprise to hear sounds that you have not heard for a long time. If you have a hearing loss only in the high pitches, hearing aids will sound sharp, echoy or tinny when you listen through hearing aids for the first time. It will seem like this to you because you have not heard high pitch sound in a while. If you have hearing loss across all of the pitches, sounds will seem loud to you when you first get the hearing aids.
To help you through the process of adapting to hearing sound again; we start by working out how much amplification you need, then taking some of it away. We will also ask you to wear your hearing aids all the time, from the time you wake up in the morning until you go to bed at night.
Your “Hearing Adventure”
At first, you will go through what we call the “Hearing Adventure” where you identify sounds you had forgotten were there. Some sounds may seem quite intense or even annoying at first because they are a new sound, and they will jump into your awareness. After a few days, the new sounds will begin to feel natural, and you will not notice them anymore. After a couple of weeks, we will see you again in the clinic. By then, you will have adapted to this level of sound and will be ready for more. We will increase the sound in your hearing aids, and you will adjust again over the next week or so.
Wearing your hearing aids all the time (even when there is nothing special to listen to) is key to your success with hearing aids. People who only wear them “when they need to hear” are usually the people who do not do well with hearing aids. They complain that their hearing aids make too much noise. It takes time for a new “normal” to develop, normal to hear. People who only wear their hearing aids sometimes do not allow their brain enough time to adjust to hearing sound.
Real-ear measurements take your individual ear acoustics into account when calculating how much gain (sound) you need in your hearing aids. The shape of our outer ear (pinna) and ear canal affects the acoustic in our ears and the way we hear sounds. As you can imagine, since everyone has a different face structure, every person has a different ear canal acoustics. The initial settings of hearing aids (when entering your hearing test into the calculation software) are based on average ear canal acoustics in the KEMAR manikin (below). It is unlikely that your ear canal acoustics will be the same as KEMARs. This means that hearing aids that are programmed using the only manufacturers expected gain levels will not have the correct gain (sound) levels. This is why we need to do real-ear measurements and then adjust your hearing aids to give the most effective hearing clarity.