You are in: Hearing problems

Hearing problems: interference, background noise and directional problems, 1 of 2

Unbalanced hearing

Background noise can be a major problem for people with hearing loss when they cannot easily distinguish one conversation from another. A common cause is unbalanced hearing which occurs when the two ears 'hear' differently in some way. Suitably adjusted hearing aids in two ears rather than one can sometimes improve matters, but for me and for countless other deaf people, unbalanced hearing has to be lived with because one or both ears are damaged.

Essentially two properly balanced ears enable people to identify the direction and position of a sound. I well remember the dramatic change after my ear operation. One of the telephones on a desk was ringing and I had no idea at all which one it was - something that would have been inconceivable to me before when  my (albeit poor) ears were at least reasonably balanced. 

Similarly I remember sitting in a corridor outside a number of doors behind which consultants were taking patients. I was called from behind one of them and I had no idea which one. I actually had to peep inside to check for some sort of recognition. (I have since wondered why the consultant didn't realise the problem and take alternative action, but to follow that train of thought here would be to digress). 

I also found, extremely disconcertingly, that sounds which once seemed to be over by the wall or outside the window now seemed inside my head. They still do. For me, the change was immediate and dramatic, so I could recognise it for what is was. For many deaf people, the problem develops slowly. They know that they increasingly dislike situations where a lot of noise is going on but they may not have analysed why.

The most distressing outcome of unbalanced hearing is in situations where a number of conversations are going on together. This is the well-known 'problem of background noise'. The only way that anyone with badly unbalanced hearing can distinguish one voice from another which is speaking at the same time is if it is louder or more strident. Even then, a babble of voices causes interference with the voice that the person concerned is trying to concentrate on. The only way to cope is through a great deal of concentration and a fair amount of guesswork. It is extremely tiring and not particularly successful. Often in such situations there is a delay between a deaf person being asked a question and their reply, which is because they have to interpret what is said before any reply is possible. They can feel incompetent and isolated, and also believe - all too often correctly - that other people are interpreting their behaviour as stupidity.

A problem with unbalanced hearing that is extremely distressing to anyone who appreciates music, is that notes can be heard at different pitches in each ear. That is certainly the case for me; I have no idea of the actual pitch of a note and just mime when situations demand that I join in singing.

It is difficult for people with normal hearing to understand how difficult unbalanced hearing can be. I remember someone announcing in a proud voice that she could home-in on one conversation and block out others - as if it was a skill to be learnt. It didn't seem to occur to her, as it probably doesn't to most people, that some deaf people simply don't have the physical equipment.

How to help someone with unbalanced hearing

Click here for How to help someone with unbalanced hearing.

Two ways to understand what unbalanced hearing is like

1. Get two portable radios. Turn one of them on and tune it to a channel where there is speech rather than music. Adjust the volume so that when you move away, you can just understand what is being said. Now turn the radio off and do the same with the other radio. Finally turn both radios on together to the volume that you adjusted before and move away again. By being some distance away, both voices will seem to come from pretty well the same point, so you won't be able to focus on one rather than the other using the pin-pointing ability of your two ears. Can you now understand what either voice is saying? It isn't easy is it? After a few seconds you will probably feel that the point has been made, but keep the two radios going for ten minutes or so. By the end you will probably feel that you want to scream! At least you will be able to locate where the babble is coming from. People with unbalanced hearing hear it inside their heads.

2. Another helpful demonstrate is through an analogy with sight. Just as two balanced ears are necessary for pinpointing sound, so are two eyes necessary to locate the precise position of any object. To see this for yourself, cover one eye and get someone to stand behind you and dangle a loop of wire in front of you sideways on. It is essential that you don't see loop or its support in advance with your two eyes and that you don't see the hand at the time of the demonstration. Otherwise your brain will rely on its memory of sizes to estimate position, rather than on what a single eye will tell it. Then try to put a pencil through the loop from left to right or right to left, not directly front-on. The chances are that you will fumble. If you really can put the pencil straight through the loop first time, your brain is almost certainly guessing correctly at some sizes somewhere. The reason for the fumbling is simply that one eye cannot pinpoint position, even though the brain can compensate to some extent using its understanding of relative sizes. The fumbling should indicate how someone with unbalanced hearing has to fumble in order to work out where sound is coming from. This may not matter too much if there is only one source of sound, but it matters a great deal when there are lots of competing sounds, like speech in a crowded room.