Question: If you only had one coping strategy you could employ, and it mustn’t cost a cent, what would your single most effective hearing loss coping strategy be?
Answer: The answer’s a no-brainer—get close—get as close as you can to the speaker’s mouth.
There are four very good reasons for you to get close.
1. Sounds Drops Off with Increasing Distance
You all know this, but do you realize just how dramatic this drop off is? If I am talking and you have your ear right at my mouth, you will hear me 100%. However, if you move just 2 feet away from my mouth, the sound will rapidly drop off according to the inverse square law, and will only be one quarter as loud. To calculate this, you put a 1 over the distance squared. In this case, it is 1 over 2 x 2 which is 1 over 4.
So just 2 feet away you will only hear me ¼ as loud. If you increase that distance to 8 feet, then you will only hear me 1/64th as loud (1 over 8 x 8). At the back of a room at say 20 feet, you will only hear me 1/400th as loud (1 over 20 x 20). Couple this with your hearing loss, and this makes a dramatic difference in what you hear.
Therefore, if you want to hear louder, get close!
2. Background Noise Becomes a Problem with Increasing Distance
With increasing distance, more sounds come between you and the speaker—and because they are closer to you than you are from the speaker, you hear them better. As a result, they drown out the speaker. This means any extraneous sounds from the audience such as coughing, papers crinkling, shifting in your seat, people talking, or any external sounds coming in through the windows or doors all make it more and more difficult for you to understand the speaker the farther you are from him.
Wearing hearing aids doesn’t really help in these cases because with increasing distance you need to turn up your hearing aids more—and when you do that, your hearing aids pick up more and more background noise which interferes more and more with your ability to understand speech.
However, if you have your ear right at the speaker’s mouth, you won’t hear any of this background noise.
Therefore, to eliminate background noise, get close!
3. Speech Becomes Distorted with Increasing Distance
As speech sounds travel through the air, they are subject to distortion. For example, reverberation and reflections off hard surfaces in a room can distort speech. The closer you are to the speaker, the less you will hear this. If you have your ear close to the speaker’s mouth, you won’t hear any distortion at all.
Therefore, to eliminate distortion, get close!
4. Speech Intelligence Drops with Increasing Distance
Did you know that the further you are from a speaker, the less intelligence there is in the speech sounds you hear? This means it becomes harder and harder to understand what the speaker is saying with increasing distance. Let me explain.
Most hard of hearing people have a high frequency hearing loss. On your audiogram the low frequencies are shown on the left and the high frequencies on the right. A person with normal hearing has a line that goes across the top on or near the 0 dB line. A person with no hearing at all has a line that goes across the bottom. However, most hard of hearing people have a high frequency hearing loss so their audiogram shows reasonable low-frequency hearing, significant mid-frequency hearing loss, and hearing that drops off dramatically in the high frequencies.
Now follow this carefully.
Most of the volume in speech is in the low frequencies which you already hear not too badly—so you hear these low frequency sounds quite well.
However, most of the intelligence in speech is in the softer high-frequency sounds which you don’t hear much of at all.
Therefore, because you can still hear low-frequency sounds reasonably well, you can hear people talking, but because you can’t hear the softer high- frequency sounds well, if at all, you have great difficultyunderstanding what people are saying. You desperately need to hear those high-frequency sounds better in order to understand speech.
Now here’s where it gets interesting.
Low frequency sounds travel quite well through air so you can hear them at a greater distance. For example, the low frequency component of a speaker’s voice easily travels to the back of a typical room.
However, high frequency sounds attenuate quite fast in air so you can’t hear them well from very far away. They rapidly drop out of the air with increasing distance. Picture the high-frequency sounds coming out of the speaker’s mouth and falling in a pile on the floor close to his feet. The mid-frequency sounds travel farther and fall in a pile in the middle of the room, while the low frequency sounds from his mouth zoom right to the back of the room.
What this all means is that the farther your ears are from the speaker’s mouth, the fewer high-frequency sounds you hear and consequently, the less you understand of what he is saying because the sounds you need to understand speech are all laying here in a pile near his feet. They never reach your ears! So, if you want to hear the intelligence in speech, you need to be close to the speaker’s mouth.
Therefore, to understand speech better, get close!
Getting Close—Here’s How
There are two ways to get close.
1. Get Physically Close
You do this by putting your ear close (closer) to the speaker’s mouth. This may work well in one-to-one situations, but won’t work in groups. Therefore,
2. Get Electronically Close
You do this by using an assistive listening device (ALD) that has the microphone close to the speaker’s mouth.
This is the beauty of assistive listening devices. The speaker wears a microphone that is very close to his mouth—maybe 5 inches away. The result is that all the high frequency sounds reach the microphone and are captured before they have a chance to fall on the floor just beyond him.
Once these sounds have been captured by the microphone, they never have to travel through the air again except for a half inch or so in your ear canal. As a result, you don’t lose the intelligence contained in the high frequency sounds.
For example, if you are using an FM system, the sounds reach your ears via radio waves—including the high frequency sounds. If you are using an infrared system, the sounds reach your ears via light waves—including the high frequency sounds. And if you are using a loop system, the sounds reach your ears via a varying magnetic field—including the high frequency sounds.
The result is that when listening to an ALD that is being used properly, you hear wonderfully clear sound (at least as clear as your damaged ears will permit). This is because you have effectively covered all your bases—you have gotten close (because the microphone is close to the speaker’s mouth), you have cut out most or all background sounds (because the microphone is close to the speaker’s mouth), you have eliminated distortion (because the microphone is close to the speaker’s mouth) and you have captured the intelligence of the high-frequency sounds (because the microphone is close to the speaker’s mouth).
Here is another thing that is important for you to understand. Hearing aids by themselves cannot do what ALDs do because your hearing aids’ microphones are at your ears, not at the speaker’s mouth—thus the high-frequency sounds from his voice still land in a pile near his feet. They never reach your hearing aids’ microphones! This is why, if you are at any distance from a speaker, you need to supplement your hearing aids with effective ALDs.
Let me illustrate this with a story that shows just how effective ALDs can be. In my Hearing Loss Association of America chapter, we use a room loop. At one meeting, I was sitting in the first row right in front of the speaker—about 10 feet away.
With my hearing aids in their microphone settings and by speechreading, I could understand the speaker, but I had to pay close attention. When I switched my hearing aids to their t- coils, suddenly the speaker’s voice was wonderfully clear—just as if he was talking into both of my ears at the same time. It was so clear that I could look away and still easily understand him.
Then I got up and walked to the back of the room. With my hearing aids back at their microphone settings I had to strain to understand the speaker. All the crispness had gone out of his voice and his voice sounded very bassy and muffled. However, when I switched my t- coils back on, wow! The sound was beautiful and clear again—just like he was talking right into both of my ears.
This is how dramatic the difference is when you get electronically close via your hearing aids and ALDs. Therefore, whether you are using your bare ears, wearing hearing aids or using ALDs, always remember that the single most effective hearing loss coping strategy is simply this—one way or another get close!
The above article was extracted from one of Dr. Neil’s recent presentations. If you want a dynamic speaker that understands hearing loss from the inside out, book Dr. Neil to speak to your group or at your next conference.