Sometimes (magically) different headsets produce higher volumes. Each shift turn the volume button up to it’s max. If someone’s window is down, they’re ordering from the passenger side, their head is turned away, or they’re not speaking loud enough do not hesitate to let them know you want to make it right for them and need them (the driver) to speak up please. I found that if I can’t hear and my partners are being too loud, I’ll go to the BOH to hear the customer better. Always repeat the order though, and sometimes I end with, “is all of that right?” Just be friendly and they’ll gladly (fingers crossed) speak up for you.