Basically, an audiobook is literally an audio recording of a book being read aloud, while text-to-speech (TTS) software is an app using technology that speaks aloud digital text such as books, news articles, magazine articles and websites on a computer or mobile device.
Audio books are recorded using the human voice, often the author of the publication or some other well-known actor or voice-over expert. Because a person reads the text, audiobook readings tend to include things like changes in tone and emotion, and pauses in the reading at natural places like at the end of sentences.
TTS uses computer-generated voice. There are many different TTS voices, and depending on the software being used the reader is able to choose the gender and accent of the voice. As technology improves the voices are sounding more and more natural. But since TTS is a digital voice and not a human voice the reading may have mispronounced words, pauses and punctuation that doesn’t make sense, and tones or emotions that don’t fit with the content of the text.
Audiobooks are usually created as a digital file such as MP3 format which can be played on computers or mobile devices and smart phones. TTS is a software program. It is often available as a pre-loaded application on many devices and a variety of TTS apps can be downloaded for the major operating platforms.
There is a difference in how audiobooks and TTS software are used with visual text. Audiobooks are used passively, listening to the spoken words of the text with or without the user having a printed copy of the book and turning the pages to follow along. If the document is in a digital format the reader may also follow the words on a screen.
Reading with TTS is a more interactive experience. The user can follow the visual text and have the words highlighted on the screen if desired. Most audiobooks do not offer this feature. TTS also allows the reader to move around in the text, jumping to different parts of the book or article and search for keywords, chapters, tables of content and page numbers.
Audiobooks are individual items. They are recordings of just one specific book. They can be purchased individually or accessed through a subscription service for a monthly or yearly fee. Most libraries now offer audiobooks for many of their titles.
TTS software is purchased once and can then be used for any digital text. Often it is provided as a no-cost feature in digital devices. Once installed it can be used for various types of publications like books and magazines, and it has other capabilities such as reading email.