9.1 WCAG 2.1 Success Criterion 1.2.4 - Captions (Live)
Ensure all audios and videos that are presented "live" have captions.
Before Rectification
When an audio is embedded in a webpage as shown above, the audio is only usable by people who can hear.
After Rectification
Text captions should be provided so that persons with hearing impairments can still have access to content from the audio as shown in the example above.
WCAG 2.1 Reference:
https://www.w3.org/WAI/WCAG21/Understanding/captions-live