This icon might seem familiar from another game that I'll let the community guess which game.
Download Link:
http://www.filefront.com/17226437/Berkelys_MGS_voice_icon.rar/How to install sprites.
1. Make back-ups of the originals (Optional)
2. Drag the 'sprites' folder to this directory:
C:\Program Files (x86)\Steam\steamapps\YOUR ACCOUNT NAME\half-life\ts
Windows will ask you if you would like to replace, just click 'Yes to all' and it will add the voice icon that I use.
3. Launch TS and test.
Have fun!
*Software you might need; WINRAR:
http://rarlabs.com/download.php