How to turn off HD voice calls?

Unicom VoLTE HD voice function can be turned off in the following ways:

1. SMS can be sent to close: send "TDVOLTE" to 100 10 and confirm Y. System reply: Dear users, your VOLTE function has been closed, which will take effect immediately. Thank you for your support to China Unicom.

2. China Unicom APP

Service handles VoLTE HD calls.

3. Online business hall

Processing-Basic business processing VoLTE HD calls

4. Cancel or call the 100 10 customer service hotline through the business hall.