The popularity of portable music players such as the iPod has made audiobooks more accessible to people for portable listening. This has led to a boom in the creation of free audiobooks from Librivox and similar projects that take works from the public domain and enlist volunteers to read them. Audiobooks also can be created with text to speech software, although the quality of synthesised speech may suffer by comparison to voice talent recordings. Audiobooks in the private domain are also distributed online by for-profit companies such as Media Bay, the BBC (British Broadcasting Corporation), Spoken Word, Naxos, Audioville, Bookstolistento and Audible.com, which in 2006 generated $82.2 million USD in revenue through sales of downloadable audiobooks and other spoken-word content.

Did you know that audio books are becoming more and more popular by each day? For example, in 2004, over $124 million worth of audio books were sold in the UK and $120 million in Germany during 2005. Experts say that this year the market is expected to rise by 20% in Europe, and audio books seem to be even more popular in the USA. A survey showed a 6 % increase over 2005 with audio book sales now estimated at $923 million. You save time, because you can listen to such books anywhere and everywhere just like an mp3 audio, and you can even do other things at the same time. You can listen when driving to and from work, when walking the dog, cycling, working around the house or at the computer, exercising, and so on. The possibilities are endless. With a fast pace of life and work on the increase, many find it hard to find the time to read. The combination of audio books and MP3 players is making it possible for people to now get their reading in where ever they go. The easy listening of to-go audio books enables multitasking while exercising, commuting, or cleaning house.

Sherlock Holmes is a fictional detective of the late 19th and early 20th centuries who made his first published appearance in 1887. He was devised by Scottish author and physician Sir Arthur Conan Doyle. Holmes is famous for his prowess at using logic and astute observation to solve cases. He is perhaps the most famous fictional detective, and indeed one of the best known and universally recognizable literary characters. Conan Doyle wrote four novels and fifty-six short stories featuring his creation. Almost all were narrated by Holmes' friend and biographer, Dr. John H. Watson, with the exception of two narrated by Holmes himself and two more written in the third person. The stories first appeared in magazine serialization, notably in The Strand, over a period of forty years. This was a common form of publication at the time: Charles Dickens' works were issued in a similar fashion. The stories cover a period from around 1878 up to 1903, with a final case in 1914.

With the development of portable cassette recorders audiotapes had become very popular and by the late 1960s libraries became a source of free audio books on cassettes. Instructional and educational recordings came first followed by self-help tapes, and then by literature and fiction. In 1970 Books on Tape Corporation started rental plans for audio books distribution. The company expanded their services selling their products to libraries. Audio books gained more and more popularity. By the middle of 1980s the audio publishing business grew to several billion dollars a year. The new companies, Recorded Books and Chivers Audio Books, were the first to develop integrated production teams and to work with professional actors. And since libraries made up the largest segment of their market space, Chivers Audio Books established close connections with them from the very beginning of the company's existence.