Quieter launches and crashes?

While I quietly assemble and fly KSP rocketships, my wife quietly reads nearby, enjoying the gentle music and Wernher Von's ah-hah's. Until I launch or crash-land one, whereupon the sudden noise makes her jump out of her chair and stomp out of the room.

By now I don't need an audio reminder that boosters have ignited or that the ship is becoming a cloud of debris.

How can I quieten, mute, replace, or disable these two loud sounds?

• Change a setting in a Unity config file?

• Delete or replace a few .wav's?

• Dual-boot into Linux and learn how to do PulseAudio filtering wizardry?

• Insert a hardware compressor-limiter between the PC's line out and the loudspeakers?

• Or resign myself to headphones?