Hearing and ageing

Many old people become hard of hearing. An important factor in hearing loss is the amount of noise we are regularly subjected to. People who work in noisy environments or who are otherwise exposed to high levels of sound are likely to lose much of their hearing by their 50s. Perception of high frequencies is lost first; it is harder for partially deaf people to hear speech because they cannot hear consonants such as ‘s’ and ‘t’ clearly.

Hearing loss is partly mechanical in its cause. The delicate bones called ossicles that convey sound energy from the eardrum to the cochlea, where it con- < The arcus senilis, a while verts into nerve impulses, no longer articulate well. Changes in the bones, or disease, may also damage the ability to conduct sound. The other changes causing deafness occur in the cochlea. We gradually lose the so-called hair cells that respond to the mechanical energy of sound. Developments in electronics have made hearing aids both small and powerful. A hearing aid cannot rectify every kind of hearing loss, however. Another disadvantage is that a hearing aid will amplify every sound, including the noises from the background.

By speaking slowly and distinctly (it is not even that important to speak loudly) and by taking care that there is a minimum of background noise (such as a car engine or aradio) it is quite possible to make the life of a person with a minor form of hearing loss considerably more pleasant.