Do you need two Ears?

Do you find it hard to listen to two things at once? Maybe you're watching the TV and someone is trying to talk to you?

If so, then it seems you might be able to blame it on your genes.

That's according to new research that has just come out from a team of scientists from the National Institute on Deafness and Other Communication Disorders (NIDCD) in Maryland in the US.

Robert Morell and his colleagues carried out a study of 194 pairs of identical and non-identical twins to investigate whether the ability - or lack of ability - to listen to more than one thing at once, can be inherited.

The twins were given a series of tests to establish how well they could pick out one sound from one ear when they were being played a different sound in the other ear - so for example they were asked to identify the two sounds "ma" and "ka" that were being played one in each ear.

The team compared the scores of the non-identical twins - who share on average 50% of their genes - with the scores of the identical twins - who have exactly the same genes.

And it turned out that the ability to listen to more than one thing at once is certainly heritable - by about the same amount as Type I dibetes.

Other than being a good excuse if you get nagged for not listening to your wife while listening to the TV, it's hoped that these studies will also lead to better understanding of hearing disorders, in which people with normal hearing have trouble understanding words.