One obvious practical advantage to listening to rather than reading a book: multitasking. With an audio tape, CD or MP3, you can enjoy a book while also doing other activities such as housecleaning, driving or cooking. An audio book can be an entertaining companion on a long road trip. People who don't have the time to sit down and give the written word their undivided attention can still enjoy works of literature in the audio format.
Some studies show that audio books can promote literacy in young readers. Children especially like have stories read to them, so naturally they find the audio book format engaging. By listening to stories, children can be more likely to sample different genres of books, more likely to learn dramatic and interpretive skills and are more able to understand new vocabulary words and how they are pronounced. Some books for children include music and sound effects, which can delight younger "readers."
Reading is a solitary activity. Listening to an audio recording can be done as a family, much in the same way families gathered around the radio in the 1930's. In addition, the audio book has a performance element. When a skilled actor or voice actor brings their dramatic and interpretive skills to a literary work, it adds a performance dimension to the experience.
Anyone who looks at a computer monitor all day might not find focusing on a book's tiny printed pages to be relaxing. For people with vision problems or people who just have tired eyes, an audio book can be a welcome alternative to reading.