Since a new Half-Life game was recently released and because I'm slightly mad, I have decided to properly document all the samples I have found for the Half-Life series soundtrack over the course of a long time, including samples used for sound effects. Some of these findings come from the "Samples Used in the Half-Life Soundtrack" videos, but otherwise I just found them here and there. There's rather a lot, so apologies for the big post:
Half-Life- “Track 7” (Sample 2) from “East West Symphonic Adventures” was used in “Adrenaline Horror”
- “Track 28” from “East West Symphonic Adventures” was used in “Adrenaline Horror”
- “Track 33” (Sample 1) from “East West Symphonic Adventures” was used in “Adrenaline Horror”
- “Deep Guts 84” from “Zero-G Cuckooland Unhinged” was used in “Alien Shock”
- “07_03_05” from “Zero-G Dream Zone” was used in “Space Ocean”
- “07_31_03” from “Zero-G Dream Zone” was used in “Space Ocean”
- “07_33_03” from “Zero-G Dream Zone” was used in “Space Ocean”
- “07_38_02” from “Zero-G Dream Zone” was used in “Space Ocean”
- “07_38_03” from “Zero-G Dream Zone” was used in “Space Ocean”
- “07_38_04” from “Zero-G Dream Zone” was used in “Space Ocean”
- “Beat 27 16-01” from “Sounds Good - Methods of Mayhem” was used in “Hard Technology Rock”
- “Trippy Seq. 3 (120bpm)” from “Zero-G Trance Formation” was used in “Credits Closing Theme”
- “Track 57” from “Zero-G Ethnic” was used in “Jungle Drums”
- “Track 62” from “Zero-G Ethnic” was used in “Jungle Drums”
- “Beat 17A 15-01” from “Sounds Good - Methods of Mayhem” was used in “Diabolical Adrenaline Guitar”
- “Beat 17B 15-02” from “Sounds Good - Methods of Mayhem” was used in “Diabolical Adrenaline Guitar”
- “Beat 19A 15-04” from “Sounds Good - Methods of Mayhem” was used in “Diabolical Adrenaline Guitar”
- “Beat 19B 15-05” from “Sounds Good - Methods of Mayhem” was used in “Diabolical Adrenaline Guitar”
- “Track 7” (Sample 2) from “East West Symphonic Adventures” was used in “Military Precision”
- “Panning” from “Zero-G Dream Zone” was used in “Steam in the Pipes”
- “Track 47” from “East West Symphonic Adventures” was used in “Nuclear Mission Jam”
- “Track 31” from “East West Symphonic Adventures” was used in “Dark Piano Short”
- “Track 50” (Sample 2) from “East West Symphonic Adventures” was used in “Sharp Fear Short”
- “Track 54” (Sample 8) from “East West Symphonic Adventures” was used in “Scared Confused Short”
- “Track 54” (Sample 9) from “East West Symphonic Adventures” was used in “Bass String”
- “Track 54” (Sample 10) from “East West Symphonic Adventures” was used in “Apprehensive”
- “07_09_01” from “Zero-G Dream Zone” was used in “Vague Voices”
- “LOOP 21” from “Zero-G Fields of Motion” was used in “Hazardous Environments”
- “Haunting” from “Zero-G Trace Formation” was used in “Cavern Ambience”
- “Open Up” from “Zero-G Trace Formation” was used in “Cavern Ambience”
- “62. Fight Scene3” from “Best Service - Sound Collection CD2” was used as a mortar sound effect
- “58 Siren Air Raid” from “Best Service - Sound Collection CD2” was used in as an alarm sound effect
Half-Life 2- “39 Synth Atmos” (Sample 5) from “Zero-G Ambient 1” was used in “Calabi-Yau Model”
- “38. Wooaauh” from “Zero-G Cuckooland Ambience” was used in “Hard Fought”
- “68.1AMB7TH” from “Zero-G Malice in Wonderland” was probably used in “Lab Practicum”
- “Didgerydon't” from “Zero-G Cuckooland Asylum” was used in “LG Orbifold”
- “Slow Guitar Rising” from “Zero-G Cuckooland Asylum” was used in “LG Orbifold”
- “Wood Vibrations” from “Zero-G Cuckooland Asylum” was used in “LG Orbifold”
- “Squeak-D#3” from “Zero-G Ghost in the Machine” was used in “Nova Prospect”
- “093 Distorted Trumpets-C” from “Zero-G Ghost in the Machine” was used in “Radio”
- “Is that the Door-G#3” from “Zero-G Ghost in the Machine” was used in “Radio”
- “57. Jungle Fire” from “Zero-G Cuckooland Ambience” was used in “A Red Letter Day”
- “55. Bamboo” from “Zero-G Cuckooland Ambience” was used in “Sandtraps”
- “Rusty Spoke” from “Spectrasonics - Distorted Reality” was used in “Suppression Field”
- “24. Trumpet Hole” from “Zero-G Cuckooland Ambience” was used in “The Innsbruck Experiment”
- “35. Dungeon Slow Mo Trampoline” from “Zero-G Cuckooland Ambience” was used in “Train Station 1”
- “5. Balancing Act” from “Zero-G Cuckooland Ambience” was used in “Train Station 2”
- “93 Metallic Moans, Reverberant, Eerie” from “Hollywood Edge - Premiere Edition” was used in “Entanglement”
- “23. Back Bendy” from “Zero-G Cuckooland Ambience” was used for Citadel ambience
- “28. Spring Fuzz” from “Zero-G Cuckooland Ambience” was used for Citadel ambience
- “29. Insects In The Oven” from “Zero-G Cuckooland Ambience” was used for Citadel ambience
- “39. Sea Moving” from “Zero-G Cuckooland Ambience” was used for Citadel ambience
- “54. Throwing Steel” from “Zero-G Cuckooland Ambience” was used for Citadel ambience
- “Alien Building Site” from “Zero-G Ghost in the Machine” was probably used for Citadel ambience
- “B-Movie Drug Head-G#2” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “Insect Infestation” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “Leaving The Gas On” from “Zero-G Cuckooland Asylum” was used for Citadel ambience
- “One too many” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “Overwhelming Feeling-D2” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “Physco Train” from “Zero-G Cuckooland Asylum” was used for Citadel ambience
- “Space Mission-C#2” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “Strafing Sax” from “Zero-G Cuckooland Asylum” was used for Citadel ambience
- “Winter Seaside Bus Shelter” from “Zero-G Cuckooland Asylum” was used for Citadel ambience
- “Winter” from “Zero-G Ghost in the Machine” was used for Citadel ambience
- “32 Computer&Random Rone FX” (Samples 1, 2 and 3) from “Zero-G Ambient 2” was used for City Scanner sounds
- “Big Fat Bastard” from “Zero-G Cuckooland Asylum” was used for Gravity Gun sound effects
Half-Life 2 Episodes- “120.2bpm Dirty Banana” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “120.4bpm Calcium Sulphate Kit” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Bumble Bee Hoover” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Didgerydon't” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Emotional Earthquake” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Foggy Day” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Monsters” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “Short Guitar Hero Lick 2” from “Zero-G Cuckooland Asylum” was used in “Disrupted Original”
- “SUCKER” from “Zero-G Ambient 1 or 2” (can't recall which one) was used in “Eine Kleiner Elevatormuzik”
- “SCIENCE DRONES - EXTREME COLD - A2” from “Sound Ideas - Drone Archaeology” was used in “Nectarium”
- “NATURE DRONES - ROLLING THUNDER BASS - E1” from “Sound Ideas - Drone Archaeology” was used in “Nectarium”
- “Shimmering-D#3” from “Zero-G Ghost in the Machine” was used “Nectarium”
- “The dead and the furious” from “Big Fish Audio - Toxic Textures” was used in “What Kind Of Hospital Is This”
- “Warheads” (assorted samples) from “Spectrasonics - Distorted Reality” were used for Citadel outside ambience
- “Toxic Disturbance” from “Big Fish Audio - Toxic Textures” was used for Citadel portal ambience