People use hearing aids in a variety of different places. Some places, such as home, are generally quiet; others, such as busy restaurants, tend to be noisy.
The amplified sound that a hearing aid wearer hears is “shaped” by the audiologist, who makes computerized adjustments to the hearing aid program. The type of sound that works well in a quiet home is not the same as the amplification that is comfortable in a noisy restaurant.
In recent years, manufacturers have markedly improved the “noise-reduction” abilities of their hearing aids. However, before you get too excited about noise reduction you need to understand that it is wonderful for some people but not for others. This article will help you understand whether or not noise reduction technology will work for you.
Hearing Aid Programs and Background Noise
Many hearing aids have a button you push to select a particular “listening program.” What is a “listening program”? Well, a good way to understand the concept is by comparing hearing aids to eyeglasses. You are probably familiar with “bifocal” lenses: the top lens is designed for long-distance vision; the bottom lens is designed for close-up work.
Similarly, your hearings aids may have more than one listening program. Let’s say, for example, that your hearing aids have two listening programs. The first program is designed for normal listening, such as talking to people across a room or listening to television. The second program might be designed for communication in a noisy dining room or restaurant. This is a situation where you need to hear the person across the table three feet away, but you do not want to hear all the noise in the room.
The amount of background noise that hearing aids eliminate differs markedly from patient to patient and from hearing aid model to hearing aid model. Not all hearing aids have noise-canceling microphones. Also, some patients—for example, people with mild hearing loss—do not benefit very much from noise-reduction technology. Let me explain.
Open-Fit Hearing Aids and Noise
If you are a hearing aid wearer whose hearing, when unaided, is near normal in the lower frequencies and has a mild-to-moderate loss in the higher frequencies, you probably wear “open fitted” instruments.
They are called “open fitted” because they leave the ear canal open. There is no solid plastic part that occludes (i.e., plugs up) your ear canal and stops noise from entering. Instead of acting like noise plugs, open-fitted hearing aids allow background noise to go into the ear naturally, without being processed by your hearing aids. That means that you are not going to notice a reduction in background noise when you activate your Program 2. The noise level, either with or without the hearing aids, is going to sound the same.
Most of the energy in background noise is in the lower pitches. If your hearing is good in the lower frequencies—we are talking about people with “mild” hearing loss— you hear background noise the same with or without hearing aids. Activating the noise-reduction system does not modify the background noise that enters your ear naturally.
PROFOUND HEARING LOSS
If you have a profound hearing loss (i.e., you are unable to hear without hearing aids), noise-reduction technology is helpful, but not spectacularly so. First of all, your hearing is poor. Secondly, when the noise-cancellation circuit are fully activated, they may remove so much sound that there isn’t enough left for you to hear well.
So, patients at either end of the hearing loss spectrum–those with mild hearing loss and those with profound–do not experience as much benefit from noise reduction as people with moderate hearing loss.
MODERATE AND SEVERE HEARING LOSS
If you have moderate hearing loss you may experience huge amounts of noise reduction when you switch from the normal listening program to the noise-reduction program. People with moderate hearing loss are usually fitted with occluding earmolds (plastic that plugs up the ear) that act like effective noise plugs when you use the noise-reduction system.
When I fit hearing aids, I check the effectiveness of the noise-reduction system by turning on a loud noise. In some cases, patients say they can no longer hear the loud noise behind them when they switch from the normal program to the noise-reduction program. It is important to remember that this is possible only for people who have moderate (or severe) levels of hearing loss and are wearing occluding earmolds.
Periodic Tune Ups For Hearing Aids
You want to be sure you have your hearing professional “tune up” your hearing aids’ noise-reduction system after you have worn them for some time. Hearing aid microphones often get dirty and lose their ability to eliminate noise.
To test how well your hearing aids’ noise reduction is working, check them in a noisy listening environment, like a noisy restaurant or shopping center. Switch between your default program and your noise-reduction program. You should hear a significant difference.
*featured image courtesy USAF