Control how your bot pronounces content in voice conversations
Bots are generally pretty good at guessing how to pronounce content, but sometimes you'll want to override the default behaviour to make the content sound better. To do this, you can use Speech Synthesis Markup Language, or SSML. You can view more in-depth documentation at Speech Synthesis Markup Language (SSML) at Google Cloud's documentation, but this topic covers the most common use cases.
Important things to know about SSML tags
There are some important things you should know about how to use SSML in Ada:
SSML uses
<speak>tags. If you use SSML in a block, the block needs to start with<speak>and end with</speak>, so the tag contains all of the block's content - not just the content you want to target with the SSML.You can nest tags in each other. For example, if you want your bot to read out an order number slowly, you can use the code
<speak>Your order number is <prosody rate="slow"><say-as interpret-as="characters">12569</say-as></prosody>.</speak>. Note that there is still only one<speak>tag that contains all of the block's content.
Anytime a block contains content to read out, the top of the block has a Play icon 
you can click to test out your content, so you can fine tune the adjustments you make to the SSML.
Pronounce characters individually
By default, bots usually try to pronounce content together as full words or numbers as opposed to reading out the individual characters. To make the bot pronounce them separately, you can either space out the characters (e.g., "A S A P"), or use <speak><say-as interpret-as="characters">CONTENT_HERE</say-as></speak>.
You can also use this technique with numbers. For example, if a caller places an order, it's much easier for the bot to read out the order number, 12569, as separate numbers, as opposed to "twelve thousand, five hundred sixty nine."
Add pauses
Sometimes you might want to add pauses to avoid overwhelming callers with information. In this case, you can use <speak><break time="Xs"/></speak>, where X is the number of seconds you want the break to last. This can be useful in cases like:
Separating steps or details in a list
Giving callers a chance to gather information (e.g., "Let me give you 10 seconds to find your order number")
Giving callers a chance to read and respond to an SMS you sent them
Change the bot's reading speed
You can get the bot to speed up or slow down; for example, it might be helpful to slow down the reading speed when reading out a long account number, or speed up through a disclaimer. To do this, use <speak><prosody rate="slow">CONTENT_HERE</prosody></speak>.
You can set the prosody rate attribute a few ways:
As
slow,medium, orfastUsing numbers, where
1is the normal speedSlow down using
.8or.9; much slower than this can be offputtingSpeed up using
1.1or1.2
Note
Changing the speed for only certain words in a sentence might cause unwanted pauses. If you try this, make sure you test it. If it sounds odd, change the speed of the entire sentence rather than just a portion of it.
Add emphasis
When you’ve got something important to say, your bot's voice can add emphasis. Use the code <speak><emphasis level="strong">EMPHASIZED-CONTENT</emphasis></speak>.
Play a sound clip
If you want to add a sound file to an Answer, use this code: <speak><audio src="URL_PATH_TO_SOUND_FILE">FALLBACK_CONTENT</audio></speak>.
The above code requires both a direct path to a sound file, and a fallback phrase to read out in case the sound file doesn't load.
Additionally, you can add attributes to play only a portion of the audio. To do this, add the clipBegin and/or clipEnd attributes to the audio tag, each with the timestamp where you want to begin or end the sound clip, like this: <speak><audio src="URL_PATH_TO_SOUND_FILE" clipBegin="Xs" clipEnd="Ys">FALLBACK_CONTENT</audio></speak>.
Lastly, here's an example of what happens if the sound file fails to load. Instead of playing the sound, the bot reads your fallback content instead.
Have any questions? Contact your Ada team—or email us at help@ada.support.