There might be a hundred variations of this mod out there. Who knows. Either way, this is my personal take on DOOM with Half-Life sound effects. Any and all sound effects are replaced with Half-Life variations for both DOOM 1 and 2. Should work on all source ports, and if you play on ZDoom-based ports you'll get additional sounds (e.g. Hell Knight with a unique pain sound). Comes with an optional tiny DEHACKED that gives the player's shotgun the pumping sound.
We now have DOOM with Half-Life 2 sound effects. The audio sources were borrowed directly from the sound files, so I may have used unused sfx lol. (cough cough super shotgun) There is no music yet, might release those as v1.1. Before saying some of the sfx is copied from HL1, it's important to know Half-Life 2 reuses audio and music tracks in their modern game (e.g. HL1 gib sound, headcrab noises)