The system bell config module has a helpful test button, which doesn't always do anything. Usually this is because a well-meaning distro has blacklisted the beep module.
May I suggest that the kcm_bell module should check whether the module is loaded, and if not, warn the user. 

For example:
    grep -Eq '^(pcspkr|snd_pcsp)'  /proc/modules  || echo $msg
where msg might be:

The system bell (PC Speaker) is a buzzer mounted on the motherboard, or a small speaker inside the case of the PC, which can produce beeps. For laptops, this is usually wired through the main speakers. Your pcspkr is currently disabled, because the kernel module is not loaded. To load it, modprobe pcspkr.
(To ensure it loads at boot time, check it is not blacklisted in /etc/modprobe.d )

Reproducible: Always

Steps to Reproduce:
1. Install a distro  (virtually any mainstream one) with the default settings.
2.Go to SystemSettings -> System Bell. Click test.
3. Hear no beep.