I cannot reproduce that on my mac (running 10.7). Make sure you have your mic input set to the right device in System Preferences. Does the test mic button work in the Steam settings page? Try doing a Validate of your build (on the game properties page) to make sure you are up to date.
ok, I checked the system preferences and it's set to internal microphone (which is what i'm using). The mic button does work properly in the Steam settings page. I validated the game cache and that didn't fix it. I'm running 10.8.2
Okay, anyone else able to reproduce this? Perhaps it is a 10.8 specific issue?
I'm having similar problem in CS:S. I have microphone correctly set in PulseAudio settings. Steam itself is able to use it correctly (including feedback), but in CS:S in settings, it seems like it's not able to use it, starting voice test confirms it doesn't work, also people reported it doesn't work when I tried it in game. But I'm not sure if it's related to this issue, if not, I'll make new one.
System info
EDIT: Interesting. I ran steam with runtime disabled, it was working. Then I ran it again with runtime enabled (by default) and it was still working. Strange.
Closing this out as I can't repo on mac and I haven't seen another report. @Majkl578 , checking the CS:S bugs would be appropriate, I suspect they already have one open for you.
Oh 3 hours too late, I just installed HL1 on Win 7 x64 via bootcamp and noticed that the button does not work in windows as well for me. I thought it might have to do with a buggy file being brought down via Steam Cloud so I disabled cloud sync, deleted the Half-Life directory and redownloaded the game, but it still does not work.
Nothing extracted yet.
The test microphone button does not seem to work in the mac build of both the CS1.6 and HL1 betas. It used to work in earlier builds. Now when pressed it flickers occasionally but gives no audio feedback in return. The way it 'flickers' is similar to the way the voice chat icon flickers when playing multiplayer so i wonder if they are related.