The entire audio channel theory is based on a simple twitter suggestion from a third party, and Dragos saying it must be correct because he has also been unable to remove audio interference from his home audio system.
He has yet to provide anyone else with anything but perfectly clean files, with signed and matching hashes from clean Windows 8 installations.
Although some of the methods he claims are rooted in things that have been demonstrated as a proof-of-concept in previous research, his claims represent added twists in ways that are very difficult to swallow. More importantly, it's based on assumptions, and not anything that has actually been analyzed.
(For what it's worth, I analyze malware professionally)