Bob Eager wrote:

T i m wrote:

Many seem to ring the bell but also knock on the glass
[...] put another doorbell behind the door just for them. ;-)

I have the parts sitting on the shelf beside me. A small 'glass speaker'
that can play a selected audio file when the bell push is depressed. I am
torn between a voice intoning "the bell has been activated, please wait"
and the start of 'Time' from Dark Side of the Moon.

I like the 2nd idea, but if it's like the couriers round here, they
knock the glass immediately after pressing the bell, even though they
must hear the bell which is in the hall.