Active noise cancellation filter adaptation with ear cavity frequency response compensation

An ear cavity frequency response (EFCR) adaptive noise cancelation (ANC) system with path-compensation over an entire main path to the eardrum (MPED) for integration in a headphone earpiece, the ECFR-adaptive ANC system comprising:

• an ANC filter system to output an anti-noise signal at a target location based on a present ANC filter configuration so that the anti-noise signal as output at the target location is an estimate of an inverse of an in-ear noise signal, the in-ear noise signal corresponding to ambient noise as manifest at the target location due to acoustical path effects of the MPED while a user is wearing the headphone earpiece in a present wearer/wearing condition relative to an outer ear of the user, the target location being at an in-facing side of the headphone earpiece;
• an error microphone to record a residual noise signal representing a combination of the anti-noise signal and the in-ear noise signal in the present wearer/wearing condition;
• a model data memory having, stored thereon, K pre-trained ANC models, each kth pre-trained ANC model having a kth anti-noise path (ANP) filter model and a kth MPED filter model previously trained on a kth trained wearer/wearing condition, K being a positive integer greater than one;
• a user adaptation engine coupled with the ANC filter system, the error microphone, and the model data memory to:
• compute, for each kth pre-trained ANC model, a kth estimated actual noise signal by using the kth ANP filter model to transform the anti-noise signal into a path-compensated anti-noise signal, and removing the path-compensated anti-noise signal from the residual noise signal;
• compute, for each kth pre-trained ANC model, a kth estimated eardrum noise signal by using the kth MPED filter model to transform the reference noise signal;
• compute, for each kth pre-trained ANC model, a kth candidate residual noise between the kth estimated actual noise signal and the kth estimated eardrum noise signal;
• select one of the pre-trained ANC models as yielding the lowest kth candidate residual noise;
• and
• direct the ANC filter system to replace the present ANC filter configuration with a new ANC filter configuration based on the selected one of the pre-trained ANC models.