User blog comment:Deathstalker666/The Sounds of Pain and Suffering/@comment-26005008-20150124094548

Also be sure to check out Shub-Niggurath’s two extra sounds: idle.wav, sight.wav, the Hell Knight’s grunt.wav, and the locked doors baseuse.wav, meduse.wav and runeuse.wav. There is no code in Quake that plays these sound files, so they are unfortunately never used. Nonetheless, they are still precached upon loading a map, which is why they still exist. This could very well be the first time that you hear these!