Hi Tom
Sorry BS5839 part 8 does indeed deal with voice alarms, what I meant to say in my earlier post is "lack of robust certification / standards", but I understand that BSi are looking to review part 8 sometime soon, with a view to beef it up a little.
That all said, Im certianly not dismissing the use of voice alarms. They do have their place.
IKEA from what I remember widely use them in their stores.
If you notice, the creche faciltiies at IkEA are always near the front door, so that in the event of a fire alarm the little kiddies are quickly evacuated
This information is relayed in the emergency evacuation message which is broadcast informing parents that their kids have already been evacuated and are safely waiting at the assembly point.
It prevents parents panicing about the weherabouts of the kids, very clever. It is backed up by a fire warden system too, to obviously catch anyone who may not be able to speak english.
Another thing to note is the intelligibility of the alarm system itself. For example have you ever been at a train station where you couldn't make out what the announcer said over the tannoy because the message simply echoed around the station?
This can occur because sound reflects off different types of surfaces or becomes lost in such a big area or sometimes because loudspeakers are positioned too close to each other.
