Comment 3 for bug 537703

I had this problem but I seem to have fixed it by doing the following:

1) removed the blacklisted pc speaker module from the /etc/modprobe.d/blacklist.conf file by commenting out the line
#blacklist pcspkr.

Then after a reboot (though I guess "sudo modprobe pcspkr" would work),

2) opened the CompizConfig Setttings Manager, then entered the "General Options" section, then disabled and re-enabled the "audible bell" setting.

The terminal bell then worked...