Your engine as you hear itYour engine, real level (the ringing gauge reads this)Blackbird 6 m away as you hear itA clank (gameplay cue): never adapted, never masked
Settling: up to 8 dB down, slowly (about 8 s), so you don't notice it happening.
Masking: anything 10 dB under your engine stops playing, and comes back when it stops.
The world comes back: hearing recovers in 2-3 s after the engine stops; the birds, the street, the client's voice swell in.