Getting Error when using TTS service with text containing special character '<'

Question

I am using microsoft-cognitiveservices-speech-sdk for text to speech. Before sending the text to SpeechSynthesizer i am creating a ssml and then passing the smml to speakSsmlAsync method.

I am getting a issue in this process , if my text contain special character '<' then i am getting error Invalid tag name '=' found in line 3 position 41. websocket error code: 1007
where my text is n<=5 here tag name is any character after < symbol.

My ssml code is -

<speak version='1.0' xmlns='http://www.w3.org/2001/10/synthesis' xml:lang='en-US'>
<voice name='en-IN-AaravNeural'>
<prosody rate='-10%'>${text}</prosody>
</voice>
</speak>

Answer 1

Hi Nokhalal Mahato!

Welcome to Microsoft Q&A Forum, thank you for posting your query here.

To use the characters &, <, and > within the SSML element's value or text, you must use the entity format.

"

> instead of >

< instead of <

"

n&lt;=5 # for text "n<=5"

<speak version='1.0' xmlns='http://www.w3.org/2001/10/synthesis' xml:lang='en-US'>
  <voice name='en-IN-AaravNeural'>
    <prosody rate='-10%'>n&lt;=5</prosody>
  </voice>
</speak>

Kindly refer below document

https://learn.microsoft.com/en-us/azure/ai-services/speech-service/speech-synthesis-markup-structure?form=MG0AV3#special-characters

Thank you.