AT five years old I was found to have defective hearing with a cut-off frequency around half that of a normal child. So for the major part of my life I know I have heard very little if anything above 11kHz. By the age of 16 my hearing range had fallen another 3kHz to 9kHz, and, thankfully, there it has stabilised. However, the intervening 36 years have seen the sensitivity of my ears fall by 25dB for one ear and 15dB for the other.

Having lived with poor hearing all my life I am not aware of what I have missed in terms of hi-fi, live music, conversation or the natural world. But the recent asymmetric drop in sensitivity has impaired my acoustic direction and focusing ability. Conversations in noisy room, cars, aircraft, or at a football match, are becoming increasingly problematic, and I will soon have to seek a technology solution to this genetic problem.

Wearing earphones with graphical equalisation giving a high frequency boost is a joy for my musical and conversational awareness, perception, and pleasure. Unfortunately, the old analogue hearing aids are lacking in this respect and generally give a nominal amplification. However, the newer digital devices are adjusted to match the characteristics of the individual ear. This development has been a boon, and would be extremely difficult with analogue technology. The snag is a price tag of well over £1,000.

The only upside to my gradually worsening deafness has been the enhancement of my ability to concentrate, and to sleep through almost anything. On aircraft I insert attenuating bungs into my ears that reduce the background noise level by 15dB, and I also use active noise-cancelling headphones that give a further 25dB of noise suppression. So, compared with normal passengers I hear the aircraft noise at least 55dB lower, and as a result I suffer far less travel stress, and I can sleep like a baby for hours.

I was contemplating the prospect of having to resort to a hearing aid when my mind jumped back 30 years to a time when I was involved with high power radio transmitters using Morse Code. When close to these installations it was not unusual for me, and others, to hear the Morse transmissions faintly, without the aid of technology. The mechanism is not a mystery. We are largely made up of water, electrolytes, salts and sugars, an ideal soup for electrical rectification. Or to put it another way, our ears can look like a cats-whisker crystal set. The only problem with this phenomenon is its unreliability; you can never predict when it's going to work, and sometimes it is an unwanted distraction.

Returning to the digital hearing aid, I began to ponder the possibility of a built-in FM radio, pager, ear piece of a mobile phone, and perhaps even active background noise cancellation. All of these additions appear feasible in the near future, if not today. Such an advance would certainly offset the high prices, but there are other possibilities. Could the inductive loops used in churches, cinemas and theatres, be built into a pocket or trouser-belt device to provide these facilities? I have not investigated this seriously yet, but I suspect so. It is no fun being deaf, but with such technology we could perhaps offset both monetary and human cost.

Peter Cochrane holds the Collier Chair for the Public Understanding of Science & Technology at the University of Bristol. His home page is:
http://cochrane.org.uk