Update custom-avatar-record-video-samples.md

Add consent video recording requirements for custom text-to-speech avatar doc.

Author: bridgeqiqi

articles/ai-services/speech-service/text-to-speech-avatar/custom-avatar-record-video-samples.md

@@ -60,7 +60,14 @@ The custom text to speech avatar doesn't support customization of clothes or loo
 
 ## What video clips to record
 
-You need three types of basic video clips:
+You need four types of basic video clips:
+
+**Consent Video:**
+   - The consent video must represent the same avatar talent speaking, following the requirement of the consent statement. Make sure the statement is correctly recorded, and each word is clearly spoken. [Get consent file from the avatar talent](https://learn.microsoft.com/en-us/azure/ai-services/speech-service/text-to-speech-avatar/custom-avatar-create#get-consent-file-from-the-avatar-talent). You can select any one of the languages supported. 
+   - The avatar talent should always face the front of the camera, without large movements. 
+   - The video should be taken in a quiet environment, and the voice should be recorded at a reasonable volume. Try to keep the signal-to-noise ratio higher than 20. Check this document for some voice recording guidance. [Recording custom voice samples - Speech service - Azure AI services](https://learn.microsoft.com/en-us/azure/ai-services/speech-service/record-custom-voice-samples#recording-your-script).
+   - Ensure that the head part will not be occluded in each frame of the video. 
+   - Make sure no other objects appear in the camera, including filming equipment, mobile phone, etc. 
 
 **Status 0 speaking:**
    - Status 0 represents the posture you can naturally maintain most of the time while speaking. For example, arms crossed in front of the body or hanging down naturally at the sides.