GREAT PLANES RealFlight 7 User Manual page 85

Overall Volume (%)-
This parameter, found when the Audio setting is selected, controls the volume
for all sounds in RealFlight.
Sound Enabled-
This will mute or unmute all sounds in RealFlight. You can select the
Mute/Unmute Audio menu item from the Simulation menu, or simply press
M on the keyboard to toggle this setting on or off.
Application Sounds-
The Application Sounds section controls the effects and voiceover sounds in
the simulation.
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