> The use of the sound is prohibited to prevent people becoming desensitized to something you should only hear in the most dire circumstances.

Please include emergency service sirens in that, too.

Don't bother, I'm not listening to them, anyway. In fact, I turned them off completely. People who actually need to talk to me will try again or reach me another way. If my research into the number shows it as part of a company I should know I'll call back.