Can be single message, or joined for multiple messages. Voice is recorded and played when pressed.
Overlay VOCA's
This allows the user to select from a number of messages; you place overlays with pictures, symbols or words over a keyboard to show which one will say which message.
Dynamic Screen VOCA'S
Dynamic screen devices display symbols or graphics on a screen and can store multiple “pages”. The AAC speaker can navigate between pages by selecting the appropriate key.