cthea, I think the nee-naw nee-naw ones are non-directional, and according to a programme I heard on the radio, were designed that way so criminals couldn't tell which direction they were being pursued from!
But (again according to this programme) there is a new kind that involves blasts of white noise that is supposed to be more easily identified. Not many emergency vehicles seem to have them though - at least round our way I haven't heard any.
I think the louder/quieter thing is slightly different - they seem to have speakers that face the front of the vehicle which makes it less noisy for drivers behind, but it doesn't help in telling you whether the vehicle is coming from the left, right, front or back - all you know is whether it's getting louder or not.
Am LOL at the problems involved with lip-reading during sex! Perhaps you could develop a sort of touch signal, you know, tap right buttock for right a bit, tap left buttock for left, tap small of back for faster, etc etc!
WRT the original debate though, I think the whole deafness thing is a complete red herring tbh, an emergency vehicle should NOT be speeding through red lights at a speed at which it's possible to kill anyone - deaf or not, perfectly sensible drivers occasionally get things wrong and make stupid decisions - it could equally have been a hearing driver who just misjudged where the sound was coming from, or a newly passed learner who panicked, or a child crossing the road who didn't think.
I'm incredibly sorry for the driver of the fire-engine, but for the defence pretend that this is somehow the fault of the deaf driver is just insulting.
Does anyone know what the verdict was in the end?