Text, voice, or video
The busiest room is not the right room. Pick the format that matches the kind of attention you can give, and the kind you want back.
Text, when you want a sentence
Text is the lowest-pressure door. You can think, you can be in a loud place, and your room stays off camera. It is the right choice when you want a conversation but not a performance. The cost is pace: people vanish mid-line, and tone is easy to misread. Write shorter than you think you should. One clear question beats a paragraph.
Voice, when face is too much
Voice keeps the warmth of a person without asking either of you to arrange a background. Use it when you are walking, cooking, or simply not in the mood to be looked at. Headphones help. Say early if you are in a public place so the other person knows why you might pause.
If you would not want a coworker to overhear the chat, do not take a voice or video match in a shared room.
Video, when you can be present
Video rewards people who are actually there: face lit, audio usable, first line ready. It punishes multitasking. If you are going to look at another screen the whole time, pick text instead. A camera pointed at a ceiling reads as absence.
Video also reveals more than you plan. Check what is behind you before you start: mail, a name on a jersey, a window onto a street you can be identified from. Tilt or crop until the frame is only what you mean to share.
A simple rule
Ask what you want from the next ten minutes. Company while you work points to text. A real back-and-forth points to voice. A face-to-face spark points to video — and only if you can give it your eyes. You can change your mind next match. You do not have to earn the right to switch.