Anyone who has a venue should always make it clear these performers need quiet attentitive audiences, those who wish to converse wre welcome to step out into the lobby or next room so as not to disrupt the performers.
The stage director or MC for the event has a duty and obligation to control any rude situations. The performer(s) should'nt have to bare that
I once had a freind explain to me the PA can work for you in a situation by cutting it's volume to a minimum setting.
And the better line from a audience member to the rude dudes was, "HEY, this aint no DISCO, take it down the street". They got quiet and left at the break.
Mudjack