If the conference participant sets his/her energy level threshold to zero (or the conference energy-level is set to zero), then
The floor_change event will never fire if the particpant becomes the loudest speaker. This is due to the line
 
If ((switch_test_flag(member, MFLAG_CAN_SPEAK) || switch _test_flag(member, MFLAG_MUTE_DETECT)) && energy _level) {
                                                                                                                                                                     ^^^^^^^^^^^^
I folks agree I'll enter a Jira ..
 
Peter