Cracking the AP U. S. History Exam 2013 College Test Preparation Ser. by Princeton Review; Tom Meltzer; Jean Hofheimer Bennett 2013 Edition Copyright Year: 2012 ISBN-13: 9780307944900 Available format(s): Classic Audio Add to Bookshelf 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.