To support speech adaptive Cards has the
speak property which contains information on how a card shoudl be read aloud to a user.
The speech tag can be annotated using SSML markup. SSML gives you the ability control the speed, tone, inflection of the speech. It even allows you to stream audio or a render a TTS audio stream from your own service, giving you a great deal of customization.
There are 2 patterns for speak property usage by a host application:
- on delivery - When a card is delivered a client may opt to read the Speak property for the card to describe the card as a whole.
- on demand - In order to support a richer accessibility model the schema supports a speak tag per element.
This allows for clients to read each element to recipients with accessibility requirements.