Madam, - James Fyres (April 23rd) challenges people's disdain of the imminent usage of mobile phones on aircraft. May I point out to him an engineering dilemma which he does not seem to be aware of?
When we speak we hear ourselves, through feedback at a certain level. This level becomes natural and a cue for how loud to speak. The earpiece in a phone blocks out some of this natural feedback and we can't hear ourselves at normal levels. Instinctively we think we must speak louder even though we don't need to.
Ordinary phones compensate for this problem by feeding back some of the speaker's voice into the earpiece. Mobile phones, to conserve battery power, omit this process. This is why people speak in raised voices when on mobile phones and why a conversation on a mobile phone can be far more noticeable and annoying than a normal conversation. - Yours, etc,
ALEX STAVELEY, Stoneybatter, Dublin 7.