You cannot talk into the microphone and stream audio at the same time.
Bluetooth uses different profiles to use the microphone and stream stereo audio. Bluetooth cannot run both profiles at the same time.
You can connect one Bluetooth audio device (that supports the A2DP and AVRCP profile) and one Bluetooth communication device (such as a cell phone that supports the HFP or HSP profile) at the same time. However, you can use only one at a time - you must switch between the connected devices.