US Patent 7492909 Method for acoustic transducer calibration

A method of acoustic transducer calibration (200, 400) using a band limited pseudo random noise source with an internal digital signal processor (209, 403) to tailor audio characteristics of an internal microphone 103 and internal speaker (301) within a communications device (101) to insure consistent amplitude and frequency characteristics of these microphone and speaker transducer devices. The method offers and advantage such that tuning of the amplitude and frequency response consistently converges to the desired filter response with a filter type offering operational stability.