Communication with extraterrestrial intelligence (CETI) by Soviet-American Conference on the Problems of Communication with Extraterrestrial Intelligence Copyright Year: 1973 ISBN-13: 9780262191067 Available format(s): Classic Audio Log in to read What's an Audio Format Audio format refers to the way an audiobook is recorded. Not all audiobooks have the same formats. Classic Audio: A human reading an audiobook without the text displayed. VOICEtext (H): Human narrator with text that you can follow along with as it reads. VOICEtext (S): Synthetic voice with text you can follow along with as it reads.