I've appended `; tput bel` to the end of long-running scripts to get the same effect.

Fun fact: the `bell` control character is part of the ascii standard (and before that the baudot telegraph encoding!) and was originally there to ring a literal bell on a recipient's telegraph or teletype machine, presumably to get their attention that they had an incoming message.

To keep backwards compatibility today's terminal emulators trigger the system alert sound instead.