In the early 2000s I recorded some demo files with voice_loopback enabled, but can't hear the voices now. I and remember hearing all the voices before a Steam update around 2007-2008 to protocol 48.
My search tells me that VALVe updated the the codecs which broke the in game voice playback.
The dlls, voice_miles.dll and voice_speex.dll aren't loaded anymore, which is why you can't hear voices to my understanding.
I know my options are to find a cracked copy of protocol 47 half-life or dig up an old hard drive with an outdated version of Steam.
Are there any alternatives? Perhaps a plugin that forces the old dlls back into the game? Not sure where to ask this or if an AMXX plugin is capable of doing this. Maybe a Meta Mod solution?
TL;DR:
Can't hear voice playback in old CS 1.6 and The Specialists demos (from 2005-2006). Are there any plugins that allow voice playback in old demos? Demos are protocol 47:5.
I enabled all the necessary CVARs for it to work. It's still a no-go.