1/3 revolutions per minute. A 12-inch LP (long playing) record had a playing time of about 22 minutes a side, so a book of 60,000 words could be recorded on 8 or 9 double-sided twelve-inch disks.

Shakespeare and Kipling were among the first authors whose works were released as talking books, along with the American Declaration of Independence.

The development of the vinyl microgroove LP in the 1940's allowed even slower recording speeds, and first 16 2/3 RPM and then 8 1/3 RPM disks became the standard.
More recently, other formats started to be used for audio books, starting with the compact cassette. Cassettes had some major advantages over vinyl, such as better portability because of the small size of the players and media. Other features were recording times of up to two hours and the fact that the tape stayed where it was left. The Sony Walkman improved portability even further.

CDs have been popular as a medium for audio books, and with the popularity of the iPod and other audio players, the MP3 format has become more widely used.

These days, you can download audio books directly from the Internet. MP3 compression technology makes audio book files relatively small and quick to download. Once you have the MP3 files on your PC, you can burn them to a CD or copy them to an MP3 player. You could even record them onto audio cassette!

There is a vast range of audio books available - business books, historical novels, best-sellers, self-help, health and recreation. Many fictional audiobooks are read by professional actors who use their abilities to bring the characters to life.

The great thing about audio books is that you can listen to them just about anywhere - in the car, while jogging or working out, in bed, out shopping. Modern MP3 players are tiny and light, and even the smallest one will usually have at least enough space for a full audio book.