sound was recorded on a continuous loop of grooved vinylite ribbon similar to the old 8-track tape. Even though the original Tefifon upon which it was based ran at 19 CPS and could hold a maximum of 4 hours, one Sound Book could hold eight hours of recordings as it ran at half the speed or 9.5 CPS. However, just like the Tefifon, the format never became widespread in use. A small number of books are recorded for radio broadcast, usually in abridged form and sometimes serialized. Audiobooks may come as fully dramatized versions of the printed book, sometimes calling upon a complete cast, music, and sound effects. Effectively audio dramas, these audiobooks are known as full cast audio books. BBC radio stations Radio 3, Radio 4, and Radio 4 Extra have broadcast such productions as the William Gibson novel Neuromancer. An audio first production is a spoken word audio work that is an original production but not based on a book. Examples include Joe Hill, the son of Stephen King, who released a Vinyl First audiobook called Dark Carousel in 2018. It came in a 2-LP vinyl set, or as a downloadable MP3, but with no published text. Another example includes Spin, The Audiobook Musical (2018), a musical rendition of Rumpelstiltskin narrated by Jim Dale, and featuring a cast of Broadway musical stars. Use Audiobooks have been used to teach children to read and to increase reading comprehension. They are also useful for the blind. The National Library of Congress in the U.S. and the CNIB Library in Canada provide free audiobook library services to the visually impaired; requested books are mailed out (at no cost) to clients. Founded in 1996, Assistive Media of Ann Arbor, Michigan was the first organization to produce and deliver spoken-word recordings of written journalistic and literary works via the Internet to serve people with visual impairments. About 40 percent of all audiobook consumption occurs through public libraries, with the remainder served primarily through retail book stores. Library download programs are currently experiencing rapid growth (more than 5,000 public libraries offer free downloadable audio books). Libraries are also popular places to check out audio books in the CD format. According to the National Endowment for the Arts' study, "Reading at Risk: A Survey of Literary Reading in America" (2004), audiobook listening increases general literacy. Listening practices Audiobooks are considered a valuable tool because of