While I sympathise with Sir Peter Maxwell-Davies' dilemma, expressed so succinctly ("Queen's composer: Fine mobile phone 'terrorists'", The Herald, June 20), I feel that his solution has little chance of success.

As he admits himself “I know there are practical difficulties over enforcing this ...”. Those difficulties arise from trying to act to alter the behaviour of the individual. It is not so difficult, technically, to provide blanket suppression of mobile phones within a confined space.

The easiest method, in principle, is to convert the theatre enclosure into a Faraday cage which entails covering walls and ceilings with an electrically conductive lining. Developments in this direction are well advanced but the technique is probably more suitable to smaller, more regular spaces such as halls and meeting rooms, where acoustics are not an issue.

Alternatively all theatres and meeting places could be licensed to install, if they so desire, radio wave transmitters directed to irradiate the auditorium with low level microwaves. If modulated with noise, and tuned to transmit at mobile phone frequencies these interference signals will swamp the genuine signals, passing through the theatre, which have been generated by the mobile phone companies. The main difficulty of such a scheme is that radio waves reflecting off solid walls can create “quiet zones” where phones may escape suppression.

An even more effective solution would be the installation of an elementary coded radio transmitter, rather than one modulated with noise. If all mobile phones are then adjusted to recognise this code, a technically simple operation, all that is then necessary is for manufacturers to implement a relatively routine electronic adjustment to all phones to make them immobilise themselves on receipt of the code. Immobilsation would continue until the phone is removed from the radio-coded space.

Unfortunately it will take legislation both to allow such transmitters to be installed, and to require mobile phone manufacturers to adjust their devices to respond to the transmitted immobilisation codes. But even so, this still seems to represent a “lower hurdle” than formulating a mobile phone law to inculcate socially responsible behaviour into all users when entering a gathering place such as a theatre.

Alan J Sangster, 37 Craigmount Terrace, Edinburgh.