The best, most technologically advanced, expensive hearing aid in the world is just a piece of junk if it is not fit well for your hearing loss. So who decides how to set a hearing aid for you? Every manufacturer of hearing aids has a formula that they use to decide how much amplification to give at which frequencies. They will all tell you that they do it the best, and they all have data to prove it. However, they are basing those numbers of the acoustics of an “average ear canal” which is a 2 ml straight tube. Picture a thimble with straight sides. Who has an ear canal that is shaped like a thimble with straight sides?! That’s correct – no one!
So how do you know if the sound coming out of the hearing aid and into your ear is just right for your ear canal and your hearing loss? You don’t – unless you measure it! Believe it or not, it is possible to put a small microphone into the ear canal and listen to your hearing aid. Not only is it possible, but it is absolutely necessary to achieve a good hearing aid fit. Studies have shown that hearing aids right out of the box underestimate the amount of amplification necessary to correct a given hearing loss. Measuring the sound in the canal is the only way to correct this problem.
How Is It Done?
Audiologists use “Real Ear Measurement” systems to accomplish this. There are several “Real Ear” systems on the market, and they all work in basically the same way. A small tube is inserted into the ear canal with the hearing aid. This is a microphone that records the sound coming out of the aid. The patient sits in front of a speaker that emits sound (usually a sentence about a carrot, of all things!) and the microphone picks up the sound and displays it on a graph for the audiologist to see. From there, the audiologist can use the hearing aid software to adjust the amplification in the aid until it meets the needs of the patient.
Here’s An Example
This patient is getting new hearing aids. When we measure her Real Ear response, it doesn’t look great. We would like the dark green line in the middle of the green band to reach the little green crosses which are “targets” for the patient’s hearing loss. This patient is not getting enough amplification – her aids are too quiet for her hearing loss and ears.
Let’s Fix It!
So, how do we make it better? We adjust the amplification in the hearing aids, giving her more volume until we reach those targets. Here is the final result – much better! Now her hearing aids will work optimally for her.
What Have We Learned?!
This is such an important process to go through, and not all audiologists have the equipment or the training to achieve these results. If you are looking for an audiologist, please ask whether they perform Real Ear measures. It’s a great indication of whether or not they will be providing the best service for you and your hearing.
© 2020 Brattleboro Hearing Center