Dark sound

Light gets a lot of praise but darkness deserves its share of kudos as well. Everyone raves about the speed of light but if you think about it darkness always gets there first. If light is the equivalent of “on” then darkness is “off” and surely in a digital age we recognise that one can’t exist without the other. In fact, darkness doesn’t only allow light to exist, darkness has its own positive qualities and can be quite healing. A new study has for instance shown that some time spent in darkness can improve your hearing.

In the study researchers used two groups of healthy mice. One group was kept in complete darkness for a week. The other group was kept in a naturally lit environment.

The researchers found that the mice who had been kept in darkness had changes in the neuronal circuits in their auditory cortex. This is a part of the brain that allows conscious perception of pitch and loudness. According to the researchers the changes they observed would equate to a human finding their hearing was more acute so they could hear softer sounds and also discriminate between different pitches more effectively.

We know that “thalamocortical inputs”, primary connecting neurons in sense-related parts of the brain, tend to deteriorate with age. However, this research shows that by switching off another sense (in this case vision by exposing yourself to darkness) can reactivate some of those other sensory connections.

This is partly why musicians like Stevie Wonder and Ray Charles have had such musical sense and it may point the way to treatment for some sensory illnesses. The researchers say that they don’t know how long a human would have to be exposed to darkness to achieve this boost to hearing and they suspect there might be other brain changes resulting from darkness exposure.

It goes to show that sometimes you have to switch off in order to switch on.