PPP Audio ads..Does anyone know of a company that places them on websites??

We have a user generated site based on audio.

We are looking for a company that can place pre and post roll audio ads on our site.

We have had a tough time finding a company that does it.

We tried netaudioads.com and they have not sent us any info

Does anyone know of a company that does a similar form of advertising??

Your help would be appreciated

Thanks

Don't bother with netaudioads, it's been in testing stage forever, you won't make anything with them