How can the mobile phone Bluetooth connected to the speaker can talk to the mobile phone at the same time can the speaker have their own sound?

Hello, as long as it's a Bluetooth speaker. Everything is ok! Turn on the Bluetooth speaker. Then start the phone Bluetooth search Bluetooth device with the phone to find the blue name of the stereo to pair. When the pairing is complete. No matter what you call. Still singing. He can do it on the stereo.