Madoka does realise what's happening through the sound, considering she can actually hear it - but the problem is that the sound isn't there much until it's already too late. In fact, it's the connecting hit that finally gets through to her, making her turn her head with a worried gaze.

She will at least leave Yoite to deal with it himself, but she's definitely going to ask if he's okay once the battle is over. These Helpmates don't seem as strong as other things they've fought in the past, but that doesn't mean they can't hurt!

So while he's busy handling the one that snuck up behind them, Madoka instead fires her arrow at one that's ahead of them, but still a bit further away. Just to make sure it stays back, so they won't get too overwhelmed with having too many around them all at once.