I have no idea what I will use this for but it's pretty cool, and in my testing it worked really well.
I wish usage instructions were included. What I figured out is this is NOT a filter, but a source. You add the source, then select two images. When there's no sound it shows one image, and when there is enough sound, it shows another image
OMG This is brilliant, I was looking for something like this for ages! Finally I did a hack that worked using the audio spectralizer blown up as a dynamic image mask, but tat only turned an image on which meant I could have no alpha channel and was just way too complicated.
Now I pop in to look for a better transition and find THIS!!!
Thankyou so much, this is a genius solution, so simple to use.