Not able to detect talk events in confBridge 10

I am using confBridge in my asterisk for conferencing.
I want to detect who is talking and who is not talking inside a conference.
For this there is an option in confBridge “talk_detection_events=yes” this sends the talk events to AMI, but it only sends the talk events when the user joins a conference and after that I am not able to see any events in AMI.
I want that whenever a user starts talking or stops talking there should be an event triggered in AMI.

Or, is there any command by which I can detect if a user is talking or not in confbridge?

Also, I want to detect keypress (dtmf) events in confbridge. There is an option “dtmf_passthrough=yes” which pass the dtmf events to the AMI, but I did not see any events when a user presses any key in a conference.

Please help me in setting up these.