Speech Synthesis Markup Language (SSML)
What is SSML?
SSML is a markup for sentences that are intended to be read out by a Voice User Interface (VUI). Similar to how you may make text in HTML bold by writing it
<b>inside b tags
</b>, you can use similar tags to denote numbers, questions, and more.
Examples of SSML markup tags
While Amazon has a few original markup tags, there are also standardized ones that may find support from other speech synthesis services. Here are some examples from both:
- amazon:effect – Let's you whisper text, for example for a game skill where you want to reveal a clue or secret to the player
- amazon:emotion – Can change Alexa's voice to sound more excited or disappointed
- audio: Plays a MP3 file mid-sentence, for example if you want to play an audio message
- break: Creates pauses of various lengths
- emphasis: Text within this tag can be made to sound stronger or softer
- lang: Used to pronounce a foreign word in the correct foreign speech synthesis
- say-as: Used to decide how text should be read out. For example, for pronouncing numbers you could choose between amounts, phone numbers, as individual digits, a figure or a fraction.