Text-to-speech also offers a number of benefits. In general, text-to-speech is most useful for short phrases or for situations when prerecording is not practical. Text-to-speech has the following practical uses:
· Reading dynamic text. Text-to-speech is useful for phrases that vary too much to record and store using all possible alternatives. For example, speaking the time is a good use for text-to-speech, because the effort and storage involved in recording and concatenating all possible times is manageable.
· Proofreading. Audible proofreading of text and numbers helps the user catch typing errors missed by visual proofreading.
· Conserving storage space. Text-to-speech is useful for phrases that would occupy too much storage space if they were prerecorded in digital-audio format.
· Notifying the user of events. Text-to-speech works well for informational messages. For example, to inform the user that a print job is complete, an application could say "Printing complete" rather than displaying a message box and requiring the user to click OK. (This should be used for noncritical notifications in case the user turns the computer's sound off or is out of hearing range.)
· Providing audible feedback. Text-to-speech can provide audible feedback when visual feedback is inadequate or impossible. For example, the user's eyes might be busy with another task, such as transcribing data from a paper document. Users that have low vision may rely on text-to-speech as their sole means of feedback from the computer.