Off-ear and on-ear headphone detection

An off-ear detection (OED) system comprising:

• a headphone having:
• a speaker configured to transmit an audio playback signal based on a headphone audio signal,
• a feedforward microphone configured to sense an ambient noise signal and transmit a feedforward microphone signal based at least in part on the ambient noise signal, and
• a feedback microphone configured to sense a total audio signal and transmit a feedback microphone signal based at least in part on the total audio signal, in which the total audio signal is the sum of the audio playback signal and at least a portion of the ambient noise level;
• and
• an OED processor configured to receive the headphone audio signal, the feedforward microphone signal, and the feedback microphone signal, the OED processor further configured to determine whether the headphone is off ear or on ear, based at least in part on the headphone audio signal, the feedforward microphone signal, and the feedback microphone signal.

A method of detecting whether a headphone is off ear or on ear, the method comprising:

• generating an audio signal based on an output of a speaker of a headphone;
• receiving, at a processor, the audio signal;
• determining, with the processor, a characteristic of the audio signal;
• and
• assessing, by the processor, whether the headphone is on ear or off ear by comparing the characteristic to a threshold.

A method of detecting whether a headphone is off ear or on ear, the method comprising:

• producing an acoustic signal at a headphone based at least in part on a received headphone audio signal;
• generating, at the headphone, a feedforward microphone signal and a feedback microphone signal, in which the feedback microphone signal is based at least in part on the acoustic signal;
• determining, with the processor, a characteristic of the headphone audio signal, a characteristic of the feedforward microphone signal, and a characteristic of the feedback microphone signal;
• and
• assessing, with the processor, whether the headphone is off ear or on ear based at least in part on the characteristic of the headphone audio signal, the characteristic of the feedforward microphone signal, and the characteristic of the feedback microphone signal.