Don,
Try this. Courtesy of Markoz.

They still don't work after reloading the aircraft? Try doing this - Open the sound.ini file, found in [FSX root folder]\Captain_Sim\727 and change SoundOffWhenSimIsSlew=1 to SoundOffWhenSimIsSlew=0 like this:

[Common]
Refresh.Time=10
Sound.Directory=Captain_Sim\727\sound
SoundOffWhenSimIsSlew=0
SoundOffWhenSimIsPaused=1
SoundOffWhenSimDialogIsOpen=1
SoundOffWhenSimSoundIsOff=1