SlackBuildsOrg/misc/beep

beep does exactly what you would expect: it beeps.

Unlike printf("\a"), beep allows you to control pitch, duration, and
repetitions. Its job is to live inside shell/perl scripts and allow
more granularity than one would otherwise have. It is controlled
completely through command line options. It's not supposed to be
complex, and it isn't - but it makes system monitoring (or whatever
else it gets hacked onto) that much more informative.

You may need to set beep executable suid; thre are potential security
issues with doing so, but the beep source code is very small and
easily auditable, and you won't get a lot of use of it unless it's
suid, but that's your call. See the SlackBuild script for the proper
variable to change if you want to install it suid.