did anyone here ever use vivox ?

[tribal heart]

Hi, for this you'll want to use the speaking indicator but for that to be useful real time you'll also need to increase the participant update frequency to not run into the seemingly static behavior you've seen. 5-10 times per second is usually good for this to feel smooth.
https://docs.unity.com/ugs/en-us/packages/com.unity.services.vivox/16.3/api/Unity.Services.Vivox.ParticipantPropertyUpdateFrequency