Audible bell for appointments

[Francesco Potorti`]

As many do, I set visible-bell to t inmy .emacs.

But I'd like Emacs to be nonetheless when an appointment is triggered.
This is what I do:

;;; Addition to 19.30
;;; Make appt-check beep when an appointment is found even if
;;; visible-bell is t
(defadvice appt-check (around always-beep activate)
  "Beep if appt-audible is set, even if visible-bell is set"
  (let ((visible-bell nil))
    ad-do-it))

Maybe the appt-audible variable should have one of three states:
nil   don't beep
t     beep or flash, depending on visible-bell
'beep unconditionally beep