Hands-free Bluetooth earpiece for a phone is a very common application using blue tooth technology. There are two types of Bluetooth headset in current market.Bluetooth headsets often are a single monaural earpiece. Depending on the phone’s operating system, this type of headset will either play music at a very low quality (suitable for voice), or will be unable to play music at all. Some headsets can play stereo music with acceptable quality. Some headsets automatically de-activate the microphone function while playing music; if these headsets are paired to a computer via Bluetooth connection, the headset may disable either the stereo or the microphone function.