Audiobook sales continue to flourish and grow by adapting to changes in technology. Audiobooks have been around in some form since 1930. In the 1980's they became a popular medium for 'reading' a book. People began to use audiobooks with their walkmans and their car stereos. With the demand rising publishers began to develop more and more audio books and today almost every book can be found in this form. One of the best uses of audiobooks is seen in schools. Students with disabilities can listen to books being read and keep up with their classmates. Publishers are now making textbooks available in audio form for students with reading disabilities and sight problems. There are two forms of audio books, unabridged and abridged. An unabridged audiobook is an exact reading of the original book, word for word. The abridged audiobook has been adapted in some way. It may have a dramatic flair, it may be shorter, or it may include extras such as music. Writers earn royalties on audiobooks as they would on printed materials.