Yes, you have to load nvaudio manually.
Every distribution offers a way to load modules automatically... You have to find out how Red Hat is doing this...
/etc/rc.local or something like this could be the right file to enter the command...
Don't really know... In Gentoo you have to enter "nvaudio" in /etc/modules.autoload but I don't think RH is doing it the same way..
It's not much to look at but it's sooo hard to find a familiy guy . . .