This proved to be a simple fix, follow the instructions. This assumes
the pcspkr kernel module is loaded (lsmod | grep pcspkr) and not
blacklisted in a file in /etc/modprobe.d
On to the next question, why? Since I began using a PC back in 1989 I have been greeted with that annoying beep from the PC speaker on various events. Over the years it has become somewhat of an integral part of the UI when working in a terminal. Mutt will beep on new mail and tab completion uses the beep as a signal. The latest rash of all desktop project terminal emulators dropping the beep is likely due to the demands of less experienced users. Understandably, they find it annoying and useless. Conversely, an old hand like me feels lost without it. Fortunately, the terminal emulator in XFCE 4.6 has an easy way to enable it.
Thanks, guys!