Have some of this in Sprint specs we can look up. The items on screen are read out. Mostly for accessibly but can be used by sighted users, and i f good, coin be very useful. Think about GPS directions, and how much its become a joke. Make it better! Alison's phone announces (badly!) callers with a text-to-voice. Use that as a good sample where it sorta crosses with reminders (it's a notification, with privacy etc. issues) as well as on onscreen readout, but also as an anti-pattern since it launches into it, and is un-understandable).

Basically, TTS (text to speech)

Fair bit about it being the output side of voice input, so together it's a voice control system

Problem

Certain classes of users, or any user in certain contexts, must be able to consume content without reading the screen.

Solution

Mobile devices must be able to read text displayed on the screen, so it can be accessed and understood by users who cannot use the screen, for any reason.

Variations

Universal - whole interface, output side (replacing the screen) for a complete voice I/O. Even if used for only one phrase, this same method is used for any readback of voice commands.

Elemental - Read a document, a web page, etc. Then ends.

Selected - Read a selection

Confirmation - In a voice I/O, reads back entry to confirm that this is what is intended.

Voice output that is presented based on conditions, such as position or time, are discussed under the Voice Reminders pattern.

Interaction Details

initiate at the moment...

set generally... in settings

Presentation Details

Audio should be played through the external speaker, or speakerphone. The last set in-call volume (or equivalent playback volume for non-phones) should be used. Whenever possible, detect the ambient noise level and adjust the volume accordingly, in order to make it audible.

When a headset is attached (either physically or by a link such as Bluetooth), the playback should default to this device, and use the last set in-call volume for this device.

Content read must be identical to that printed on the screen. The condition that resulted in user employing Voice Readback may be temporary and transient; the user may switch between the screen and audio channels, or may even read along with the voice output. Even for users with a vision deficit, others may be accompanying them, who may also wish to use the device.

There may be delays between phrases, or before the start of the audio readback. To inform the user that audio is about to commence, and to prepare them for the volume level, a subtle tone should be played immediately beforehand.

A similar tone should be used when Voice Readback has completed for a significant time, or for the selected setting, to confirm this condition to the user. Otherwise they may be left guessing due to just

Antipatterns

Avoid mixing readback of commands and text. When the two must be used together, use delays, tones, changes in voice and clear syntax "You said..." to indicate the difference.

Examples