Hearing is an extremely complex system, the first of the five senses to be developed in the foetus. Together with sight it is considered the most important sense for being connected to and interacting with the world.

Being able to hear is essential for verbal communication and for understanding speech, so that we can relate to other people and feel part of a community. Hearing is important for appreciating the sounds which make life more enjoyable but it is equally important for people to be able to understand and react to the outside world: imagine what would happen if we couldn't hear a car braking or a gas sensor alarm or the cry for help of a person in danger.