Amazon’s Audible is the king of audiobooks. The Eisenhorn Omnibus (which includes Xenos , Malleus , and Hereticus ) is available as a single, massive audiobook.
The Black Library is the official publisher. They sell MP3 and CD formats directly. eisenhorn: omnibus free online audiobook
: Many "free audiobook" sites are fronts for phishing or malware. Amazon’s Audible is the king of audiobooks