Text-to-speech refers to the conversion of written words to a voice output by means of speech synthesis, an artificial way of allowing access to verbal communication in an alternative form. Text-to-speech technology refers to software and hardware that provides speech output from text input. This technology can create words from stored phonemes—individual speech elements—and may also store whole words and phrases for better results. Text-to-speech technology has a wide range of applications.
At least some computer operating systems have text-to-speech technology included. Apple® Snow Leopard® has ‘Text to Speech’ settings available in both a ‘Speech’ section of ‘System Preferences’ and a ‘Universal Access’ section, which addresses the usefulness of the text-to-speech technology both as a convenience and as an aid to people with visual impairment. User choices concerning the text-to-speech technology include the voice used, the speaking rate, whether to announce alerts or applications requiring attention, and whether the time should be announced aloud. ‘Universal Access’ provides access to the ‘VoiceOver Utility,’ which provides more options for controlling the voice. This is an example of the category of application called screen readers or personal readers.
Screen readers can serve a variety of functions besides assisting people who are visually impaired. They can allow auditory learners to access educational material in the way that is most helpful to them. They can assist in foreign language acquisition. Other benefits of these readers are helping with proofreading and reducing eyestrain. Perhaps more importantly, because they can and will read anything on the screen, they can allow people who have — for one reason or another — lost the power of speech to join in a conversation, and the voice in which a person communicates can be made from recorded material of their own voice, if this is available. Film critic Roger Ebert, who lost the power of speech due to surgery, after using one of the Mac OS voices had a voice made from tapes of his own speech.
The voice-activated email and text message access program called iLane® is an example of a text-to-speech technology meant to be used in a vehicle and make message access safer when en route. Because email and text messages are rendered aloud and the driver accesses the technology through voice-activation, the driver does not have to take his or her eyes off the road in order to access and/or respond to these communications. Other devices are made specifically to vocalize GPS data and to read books aloud: such is the case with a number of ebook readers.