Beamforming Designs Robust to Propagation Model Estimation Errors for Binaural Hearing Aids

Abstract

This work introduces new binaural beamforming algorithms for hearing aids, with a good robustness to errors in the estimated target source propagation model. Two different binaural beamforming designs are proposed. One design is based on an adaptive null positioning scheme, and the second is based on a combination of the adaptive null positioning scheme and wider beampatterns. Simulations are performed using signals and propagation models obtained from multichannel binaural hearing aids recordings, including some in a mildly reverberant environment. Evaluations are done in terms of noise reduction and target distortion. Evaluation results illustrate the robustness of the two proposed designs to errors between the true and estimated directions of arrival for the target source, and to mismatch between the anechoic propagation models used for the beamformers designs and the reverberant propagation models used to generate the signals at the sensors or beamformer inputs. Both designs surpass the performance of standard binaural Minimum Variance Distortionless Response (MVDR) and binaural Generalized-Side Lobe Canceler (GSC) beamformers.

Keywords

• Hearing aids
• noise reduction
• robust binaural beamformer
• source propagation model error
• direction of arrival (DOA) estimation error
• head related transfer function (HRTF) mismatch