Library /sys$common/syshlp/lse$menu.hlb SET_BELL_BROADCAST  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Syntax:  SET BELL BROADCAST boolean

  Sets the state that determines whether or not terminal bell sounds
  when broadcast messages are written to the message window.

  LSE prompts you for a value.  Specify the parameter value off to
  disable the bell for broadcast messages.  By default, the bell is set
  on.