Dynamic range and loudness
Also said as Loudness, LUFS, Compression, Night mode
Dynamic range is the distance from the quietest sound to the loudest, in decibels. Loudness is how loud the whole game seems over time, measured in a unit called LUFS.
Wide range feels cinematic in a quiet room, and on a phone it means whispers you cannot hear and explosions that hurt. Games offer settings for this because the room is unknown.
Say it
“Master the game to -24 LUFS on console. Add a night mode that squeezes the range from 39 dB to about 12 dB, so whispers carry and explosions do not wake anyone.”
Where you’ve seen it
PlayStation's target, per Wwise's documentation, is -24 LUFS on average, give or take 2. An earlier Sony working group set -23 for PS3 and -18 for Vita. Battlefield: Bad Company took another path with "HDR audio", which DICE described as measuring loudness at the listener and scaling every sound, not compression.
Not to be confused with volume
Volume is one number at one moment. Dynamic range is the spread between the extremes, and it stays the same when you turn your speakers up.