That is totally up to you and how well your mic picks up ambient noises. I believe, for the most part, they encourage you to use a push-to-talk key for standard coms. You will be using push-to-talk for all TFAR coms on the radios, so the TeamSpeak "normal" speak will just be to those in your radius (radius changes based on whether you're on whisper/normal/yelling, not the volume but just the radius).
Hope this helps/makes sense lol - I'm finding it difficult to communicate this via text lol