What does this pounding mean?

LEUTNER.

That's to rescue good taste.

WIESENER.

Well, then I won't be the last, either. (He stamps.)

VOICES.

Be quiet, or you can't hear the music. (All are stamping.)

SCHLOSS.

But, I say, we really ought to let them go through the play, for, after all, we've given our money anyhow; afterward we'll pound so they'll hear us out doors.

ALL.