Robust active noise cancelling at the eardrum

A hearing device, comprising:

• a receiver;
• an inward-facing microphone;
• an outward-facing microphone;
• a memory;
• and
• one or more processors programmed to:
• measure a receiver-to-inward-facing microphone response during an in-situ calibration stage for the hearing device;
• estimate a receiver-to-eardrum transfer function using the measured receiver-to-inward-facing microphone response;
• measure an outward-facing microphone to inward-facing microphone transfer function for an external noise sound field during run-time operation of the hearing device;
• estimate an inward-facing microphone to eardrum transformation for the external noise sound field in the inward-facing microphone using the measured outward-facing microphone to inward-facing microphone transfer function;
• compute an ANC controller using the estimated receiver-to-eardrum transfer function and the estimated inward-facing microphone to eardrum transformation;
• and
• cancel acoustic noise for the hearing device using the ANC controller.

A hearing device, comprising:

• a receiver;
• an inward-facing microphone;
• an outward-facing microphone:
• a memory;
• and
• one or more processors programmed to:
• measure a receiver-to-inward-facing microphone response during an in-situ calibration stage for the hearing device;
• estimate a receiver-to-eardrum transfer function using the measured receiver-to-inward-facing microphone response;
• measure an outward-facing microphone to inward-facing microphone transfer function for an external noise sound field during run-time operation of the hearing device;
• estimate an inward-facing microphone to eardrum transformation for the external noise sound field in the inward-facing microphone using the measured outward-facing microphone to inward-facing microphone transfer function;
• compute an ANC controller using the estimated receiver-to-eardrum transfer function and the estimated inward-facing microphone to eardrum transformation and a computed variability of the estimated receiver-to-eardrum transfer function and the estimated inward-facing microphone to eardrum transformation;
• cancel acoustic noise for the hearing device using the ANC controller;
• and
• update internal models of acoustic paths within the hearing device using the computed variability of the estimated receiver-to-eardrum transfer function and the estimated inward-facing microphone to eardrum transformation.