Since the beep you want to silence is shell-specific, I would set in in .bashrc for both console and xterm with something like:

case $TERM in      
    xterm)
        xset b off
        ;;
    *)
        setterm -blength 0
        ;;
esac

When launched as a login shell, bash reads:
1a) /etc/profile
1b) ~/.bash_profile
1c) ~/.bash_login (if ~/.bash_profile doesn't exist)
1d) ~/.profile (if ~/.bash_profile and ~/.bash_login don't exist)

When launched as a non-login interactive shell (by typing “bash”), bash reads:
2) ~.bashrc

When launched as a non-login non-interactive shell (in scripts), bash reads:
3a) $BASH_ENV 3b) $ENV (if $BASH_ENV doesn't exist)

To ensure that all three types of bash shells are launched with the same environment you need to make sure that: - $BASH_ENV exists and is set to the primary configuration file - that ~/.bashrc is the primary configuration file (since it is the only one that non-login interactive shells read) - that at least one of the login shell's configuration file exists and points to ~/.bashrc

Pick ~/.bash_profile (otherwise ~/.bash_login or ~/.profile may never get read) and make sure it contains the following two lines:

   export ENV=~/.bashrc i
   [ -f ~/.bashrc ] && . ~/.bashrc

Now, no matter how it is invoked bash always sources .bashrc and you always have the same environment.

XFree86 documentation specifies that programs reference settings in:

$XINITRC (by default = .xinitrc)
.Xinit
.xinit
.Xinitrc
.xinitrc
.xsession
in that order.

Either the Xorg developers simplified things, or else people just stopped using most of them, and the only ones mentioned for Xorg are:
$XINITRC
.xinitrc

— Contributed by Jason Armstrong: http://linuxbasics.org/pipermail/qna/2005-October/002175.html