Q: Why can’t I hear when there is a lot of noise around? I thought the hearing aids were supposed to get rid of background noise.
A: The answer to this is complicated, but I will try to explain it in layman’s terms. Firstly, there is no hearing aid made that can completely get rid of background noise. It’s impossible without carrying around machinery that may or may not fit into a backpack and weigh as much as 15 lbs. Even then, you constantly have to be adjusting that machinery to account for the changing soundscape, and constantly adjusting the microphone(s), to aim them where the sound you WANT to hear is coming from. Have you ever seen the handheld microphones with what looks like a satellite dish surrounding it? You would need at least two of those.
That being said, you still wouldn’t “get rid of the background noise, you would simply lower the intensity of it and focus in on the sound you wanted to hear. And get a hernia or be tempted to not even bother carrying all that equipment with you every time you went outside for a walk. Who would do that? Well there are some techies who do this, where they get the money I have no idea, even on e-bay they go for as much as $600, depending on the quality and how long they have been in use. And they would need TWO of them! Then there’s the amplifier, the graphic equalizer, the condenser, usually designed by said techie, by the way, a friend of mine put together a really good one for just under $7000. Then there’s the car battery he needs to power it; lifted one of those lately?
Now you have to consider that if patients are going to consider wearing these at all, they have to be significantly smaller, and require a much smaller, much lighter power source. Well, the fact is there is only so much you can put into a piece of plastic that will fit either in or behind your ear comfortably, and still have room for a battery.
And yet, hearing aid manufacturers have made great strides in doing just that. The technology behind modern directional microphones on hearing aids has gotten to a point where they can pinpoint a audio source with an accuracy of 15 or 20 degrees on either side of a centre line, or 30-40 degrees total. Are the results perfect? No, but the chances of understanding a conversation in crowded room have increased significantly. Now, what if we were to move that centerline? Let’s say the person you’re listening to is off to your left side; having a directionality going the same direction as your nose wouldn’t really help much, would it? New hearing aids can detect where the sound is coming from, and move the directionality to the source of the speech. And yes, it can prioritize speech over other noises, too. Not only that, but as the source moves, the hearing aids can track it and keep it in focus.
Now, there are times that they will have problems; sitting with one person on each side will slow the process down, for example, as they take turns talking. Also, having a steady source that is talking to another person can throw it off as well; so if you’re watching a television on your right side, and talking to someone on your left, there is problem. One or the other will have to be sacrificed. Manually overriding the direction finder can help a lot, many hearing aids are capable of that.
The other issue, which you may have gleaned from what I’ve said so far, is that in order to fully realize the benefit, you must wear two hearing aids. Wireless communication between the two hearing aids is the key to this process. Together, the chips inside the hearing aids prioritize which sounds should be amplified and which should be dampened, all within a fraction of a second, usually 4 or 5 times per second. Without that cross communication, there is not enough information to properly make such a calculation. The results have been very good. For those willing to pay for such technology, (see previous article), it makes their work life, home life and social life a lot less stressful. And that is an important factor to consider. We are social beings and the inability to hear properly is among the top reasons that people with untreated hearing impairment stop socializing, stop leaving the house, isolating themselves from family, friends and co-workers.