In a game, I have no speaker icon next to my name in the player list, so, no voice chat. It works in every other game and flavor of HL, just not in NS. I haven't found anything in these forums that have helped.
When I press my talk button I see an icon in the corner that has an exclamation point in it. Any assistance is very much appreciated.

I don't think NS shows the speaker icon next to names in the scoreboard (I assume you're referring to these).

the icon in the corner means that voice recording is on. use the console command voice_loopback 1 (0 to disable) to loop back your mic and see if it is recording your voice properly.

if not, do the standard checks (make sure you're using the proper sound-recording device, mic works, etc, etc). hope this helps.