In the zip is a wav file that will replace the new "pull Up Pull Up" F-15C and A-10A Betty warning with an "Altitude Altitude" warning that is also from the real A-10.
I have always used this file since I find it a bit easier on the ears.
Just place it into the LockOn/Sounds/Computer/USA folder but back up the original first.
If it doesn't work in that folder then place it into the Lock On/Sounds/EnglishVersion/USA/Computer folder.
The file is here: http://www.mts.net/~shepski/PullUp.zip
Known as "Stinger" in a past Flanker existence.