GMod voice chat freezes my game

When I do the push-to-talk voice chat, my game freezes or hangs for about 1-2 seconds, then transmits (but it transmits no sound). Incoming voice is fine, its just outgoing voice. I have other source games like DotA 2 , and my voice chat is fine there, so I don’t know what’s causing my mic to lag the game in GMod.