How not to miss a timeout request

[Lotto]

Last night I was working HS girl's varsity, two-man crew. With about 10 seconds left in the game, the home team scores to pull within two point. After a timeout, I'm the new lead. The home team is pressing, and I'm standing near midcourt tableside. My partner is near the far sideline and off the endline as the new trail. The home team steals the throw-in and passes to a girl near midcourt and the far sideline -- in my primary now as the new trail, so my focus is on her and I'm moving out onto the court to referee the ball. She then makes a bad pass that sails out of bounds. All of this happens within a couple of seconds. At that point, the home team coach tells me that she's been trying to call a timeout. This was a big game, the crowd was loud, the gym is one that has a high ceiling and is echo-y, and the coach does not have a loud voice. I simply didn't hear her.

My question -- is there something that I/we could have done to catch that timeout? I don't think I can be peeking behind me to see if she's requesting a timeout since I have to keep my eyes on the girls on the court in a tight, pressing situation. Is this something my partner should have picked up? Or is this just yet another reason why three-man crews are vastly superior to two? How could we have handled this better, mechanics-wise or other-wise?

Thanks for the advice!