The standard digital talking-book machine has eight controls and provides basic functionality for the playback of talking books, including volume and tone control, rewind and fast forward, and variable speed. The advanced digital talking-book machine has additional controls for setting bookmarks and navigating through the structured levels (chapters, sections, etc.) of a book. Both machines can be operated on a built-in rechargeable battery and have an internal audio user guide, as well as a key describer mode.