Patent attributes
In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.