HC Deb 16 April 1969 vol 781 cc1129-30
7. Mr. Archer

asked the Minister of Technology whether he will take steps to encourage research into the elimination or reduction of noise from industrial processes by producing sounds of a frequency range inaudible to the human ear, baffle mechanism, or otherwise.

Mr. Fowler

Noise inaudible to the human ear is of very low or very high frequency outside the range of roughly 16–16,000 cycles. It is not possible to alter the frequency of sound after it has been produced. Work on problems of industrial noise is already in progress at several of the Ministry's establishments.

Mr. Archer

Can my hon. Friend confirm from what is already known that in this field a relatively modest investment can produce disproportionately high results in terms of sheer savings to the economy?

Mr. Fowler

That may be the case occasionally, but in general any method of making a machine more silent will almost certainly make it more expensive. The object of research is to obtain as great a decrease in noise as is consistent with reasonable cost.

Dr. Ernest A. Davies

Is my hon. Friend aware that noise levels even at frequencies which are not audible to the human ear can be physically damaging, and that health costs should also be taken into account as well as simply the on-costs of the piece of machinery which is being produced? This is really becoming a very urgent matter.

Mr. Fowler

I am well aware of the health hazard that can occur even from noises which are inaudible to the human ear. Indeed, there might be greater danger if there was a considerable volume of noise equivalent at levels inaudible to the human ear of which people were unaware.