Is this something new to the 8300?? My other BB have never done this....
This speed dial sound is found on the 8300 and 8830, both of which have BB v4.2.2.x. It is not on the 8800 I have which is v18.104.22.168. It may be available in a later OS release for AT&T.
The sound itself seems to be Profile controlled. I switched to Quiet, and the speed dial tone was muted.