Equalization.

Detailed Explanation on Instagram: "The sound design process for Halo 3 took several months and involved a dedicated audio team at Bungie, led by sound director Jay Weinland and composer Martin O’Donnell. While there’s no exact public figure for how many total hours or days it took to gather and implement all sound effects, the overall audio production—encompassing recording, designing, editing, mixing, and implementing sounds—spanned a significant portion of the game’s multi-year development cy