Originally Posted by Raul_SJ
In your 40 years of experience, how often does it happen? i.e., the serving team hears a let that the receiving didn't?
I think it's incumbent on the receiving team to hear the let. If they don't call it, play out the point. It keeps thing simpler and more in the spirit of "Each team calls shots on their side of the net...".
The person closest to the net is almost always the server's partner.
If the receivers are playing two back, then they are even less likely to hear a let.
There are times when players are supposed to make a call for something that did not happen on their side of the net. Calling your own second serve out. Calling a through. Calling a ball that opponent hit into a permanent fixture before it landed in your court.