um... FYI sonic weapons dont work in space, and are usually limited to close range
You might read Harry Harrions "Eden" series, it is a good dicotomy of Man using technogly (granted it is very low tech) and a civilization based on Bio technology.
I am using that for some hints to the eventualy Vong Demise. Elementsw of non-vong galaxy taking thier toll (we hae allraedy seen thier Big ships are in disrepair, and they are having a hard time keeping up w/ thier loses) Maybe a Sith Poison or viruse that infected Ulic Qel Droma in the "Tales of the Jedi" series. Be interesting for the Jedi having to use a Sith weapon to defeat the Vong.
Maybe that is the NR salvation, using forbiddon, dangerous sith technology