Background noise has always been a problem for people with hearing loss. Without hearing aids, background noise drowns out what little speech they can hear, making it very hard to understand those with whom they are conversing. When wearing older analog or even earlier digital hearing aids the background noise often seemed louder than the person talking in front of you. Much of the problem is where the microphones of the hearing aid are located and what type of microphones they are. It has been found that where the location of the hearing aid microphones, the type of microphones, and how adaptive the microphones are have a significant affect in how well the hearing aids work in a noisy environment. To be honest, there will always be background noise. There is no hearing aid that can eliminate background noise, and if they did, that would not be “normal” hearing and you might not like that either.
Considering that background noise is such a significant problem, hearing aid manufacturers have spent millions of dollars researching how they can improve speech discrimination in noise. The first major improvement was the utilization of directional microphones, which pick up sound from the front. If your hearing aid has only one microphone, it is probably an omni-directional microphone that picks up sound all the way around. The omni-directional microphone works best in quiet environments and the directional-mic would be used in a noisy setting as in a restaurant when you want to hear the person in front of you and soften up what is coming from behind. Studies have shown that this technology really does improve a person’s speech intelligibility in noise. Originally, one would have to flip a switch on their hearing aids to change between the two microphones. Today the microphones are better and in the better hearing aids they can automatically switch from the omni-directional microphone to the directional microphone when there is speech present in noise. Some of the microphones are adaptive in that they tend to follow the speaker you are listening too.
With the advent of digital technology, the circuits are better able to tell the difference between noise and speech. For instance if the computer chip recognizes the sound to be a steady state noise, like a fan or an air conditioner, it will soften it up. If it recognizes it to be soft speech which produces a more modulated sound wave, it will raise it. If it is loud speech it may soften it for you. The goal of the hearing aids is to make loud sounds comfortable and soft sounds audible. If you have already made the transition from analog to digital hearing technology, you probably have experienced it. The first sounds that are noticed are sounds like: clocks ticking, chewing, water running, paper rattling and along with that, quiet speech. In addition, when you turn on a vacuum cleaner you may notice that it gradually becomes quieter. The greatest advantage of digital technology is that when someone does complain about a certain noise, adjustments can be made to the hearing aid through a computer. By making minute adjustments to the programming of the hearing aid specific problems can often be solved.
Today the best digital hearing aids use “wireless” technology which allows the hearing aids to process the sound together. One hearing aid knows what the other one is doing and hearing. With this information the hearing aids microphones, noise reduction, gain of incoming sound, compression of loud sounds, and more, adapt accordingly. This allows for the best possible understanding and hearing in noise by improving the localization of sound, the level of speech, and the comfort level of the noise. One manufacturer that does this well is ReSound. Their best Verso 9 technology utilizes Binaural Fusion.
Yes, there will always be noise and we cannot eliminate it. But, believe me the hearing aids today are not the same as the ones that your grandfather wore in his dresser drawer because everything was way too loud.
To hear the difference this new technology can make your hearing professional may be able to let you listen to it right in their office .
By Susan L. Fenrich, BC-HIS, Licensed Hearing Instrument Specialist, Board Certified in Hearing Instrument Sciences