I never played with a mic at all (Well, technically I did, but it was just for playing motivational nasheed at half-time and Tables Turnover at the end of the match) so I always just took orders, occasionally typing very quickly during reloads or something.
Apparently my typing speed has actually impressed people with the amount of info I can get out while fumbling around with a magazine, so that's cool I guess, this is a skill that has transferred well to Insurgency.