In 2x2 game often you need assistance from teammate: ask for minerals, ask for scan, ask for help, etc... Usually, when everything is more or less ok, you can just Alt+click on the minimap to take attention or write a text.

But in case when a lot of events are going, your teammate just don't see your.....

How to bring his attention in this case?

P.S. this is for case of microphone absence.