then it may be the pcspeaker.....a tiny speaker inside your case that can only beep.
post the output of this command pls...to see if you have it running
lsmod | grep pcspkr
pcspkr 2396 0
Now I do not use your distro but with root powers you can edit something "like" /etc/modprobe.d/blacklist.conf
add a line
reboot to test.
2) or add a line to /etc/rc.local if you can not find any blacklist file but it needs the full pathway