Auto-calibrating noise canceling headphone

A sound system comprising:

• a headphone including a transducer and at least two microphones disposed over the transducer and adapted to receive sound radiated therefrom;
• an equalization filter adjustable between a first position and a second position, and adapted to equalize an audio input signal based on at least one predetermined coefficient;
• a loop filter circuit adapted to generate a filtered audio signal based on the equalized audio input signal and a feedback signal indicative of sound received by the at least two microphones, and to provide the filtered audio signal to the transducer;
• and
• a controller programmed to:
• provide a second audio input signal indicative of a test signal to the equalization filter, when arranged in the second position, in response to a user command;
• calibrate the headphone by updating the at least one predetermined coefficient of the equalization filter based on a second feedback signal indicative of a test sound received by the at least two microphones;
• and
• control the equalization filter to receive a first audio input signal from an audio source, when arranged in the first position, in response to the at least one predetermined coefficient being updated.

A computer-program product embodied in a non-transitory computer readable medium that is programmed for automatically calibrating an active noise cancellation control system with an equalization filter adjustable between a first position and a second position within a headphone, the computer-program product comprising instructions for:

• controlling the equalization filter to be arranged in the second position in response to a user command;
• generating a test signal;
• filtering the test signal using the equalization filter and a loop filter;
• providing the filtered test signal to a transducer of the headphone, wherein the transducer is adapted to radiate a test sound in response to the filtered test signal;
• receiving a test feedback signal indicative of the test sound received by at least one microphone of the headphone;
• updating a coefficient of the equalization filter based on the test feedback signal;
• and
• controlling the equalization filter to be arranged in the first position to connect to an audio source for receiving an audio input signal in response to the coefficient being updated.