Sound

The engine runs behind the flight, its note and its loudness read off the throttle lever, and the wind rises over it with airspeed - faster than the airspeed itself, so a standstill is silent and a dive is loud. Nothing is heard until the flight is started, because a browser will not let a page make a sound before a key has been pressed at it, and nothing is heard while the simulation is frozen by the pause menu, the start screen, or the settings panel: an engine running behind a paused frame would be a frame that was not paused.

M mutes and unmutes both, marked by an AUDIO MUTED line above the artificial horizon, and the choice is stored for the next session. Muting fades the levels to silence rather than tearing the sound down, so unmuting picks it back up where it was.