Read aloud can be another name for TTS. It typically refers to audio that is synchronized with the reading itself in some fashion. TTS can do this but it is also possible to synchronize recorded voice.
This feature is often used to support partially blind readers. It also adds value to any person learning to read, although mispronunciation is one of the dangers in some read aloud techniques such as TTS. It can also be used by someone learning a new language where the audio is used to translate the text.
Some specialized formats are used to support a read aloud feature. These include SMIL and LRC. DTBooks specifically identifies read aloud as part of its DAISY format. ePub 3 and PDF readers often have read aloud support.
- Kindle eBook readers often have a TTS feature.
- iBooks supports read aloud.
- Cool Reader has support for read aloud.
- A command line eBook reader called eBook speaker will actually use TTS to speak to you. It can read ePub and LIT files as well and many other formats. The software is free.
- Menestrello read aloud support for ePub 3.
- Artifex4 READER supports narration using the Speech Synthesis API, available on Windows phone.