If you want the ability to choose between audible and visible bell on a
console basis, you can use two different terminal types for the linux console.
You can name them, for example, console and console-vb.
The console entry would be the original one, while the other
could feature a visual bell string for the "bl" item.
Thus you can change the behaviour of your bell on a console basis:
tcsh: "setenv TERM console-vb" to get a screen flash,
and "setenv TERM console" to get the audible beep.bash: "TERM=console-vb; export TERM" for the flash,
and "TERM=console; export TERM" for the beep.termcap format allows to define a terminal-type in terms
of another, so you need to insert in the database only the differences.
Refer to the manpages for more information.