After the creation of a QRadioTuner object, fm receiver gets powered up and audio starts without the need to call start(). Calling the methods start() and stop() is not changing anything and the only way to stop it is to delete the object directly. Stop() method should power donw the fm receiver, instead radio keeps working even after the radio app is closed and if there is an incoming call radio can be heard. Not only this, but microphone is not set as input till headphones (only if these have microphones like the stock ones) are plugged off: so if someone uses the radio without stock headphones he must reset the phone, or change the amixer values or start and close another radio app.