Posted By John Haywood Not come across this myself, though I was aware before your post that it is possible for 'acoustic feedback' to occur under the situation you describe. Most phone systems feature a small micro chip called a V.O.G.A.D. (VOltage controlled Gain Adjusting Device) which, is supposed to maintain a constant audio level at the ear piece irrespective of how low or high the audio level is at the microphone (as this is also adjusted automatically to maintain a constant level - unless of course your system didn't have one. High frequency, high volume audio can easily pierce an ear drum so I would get your system checked. I would presume this would come under PUWER though someone more knowledgeable than me will no doubt be along shortly with a more precise, legislative quotation.

Posted By Sarah Milroy This is something that we have been concerned about with a large number of call centre operators in our business - espcially when they can't necessarily get the speaker part of the phone/headset away from their ear in a hurry. If you do find any good information about it, I'd be grateful if you could perhaps post it back or email me smilroy@slb.com Many thanks Sarah

Posted By Ashley Williams Peter, I have a factsheet and information on acoustic shock if youd like one drop me an e-mail with name, address etc I need the information for my National Lottery Records. Ash