Combined Active Noise Control and noise reduction in Hearing Aid

This paper presents a combined active noise control and noise reduction scheme for hearing aids to tackle secondary path effects and effects of signal leakage through the fitting. While such leakage contributions and the secondary accoustic path from the reciever to the tympanic membrane are usually not taken into account in standard noise reduction systems, they appear to have a non-negligible impact on the final signal quality. Integrating an active noise control system in the existing noise reduction algorithm helps to compensate for these effects. A Filtered-x Multichannel Wiener Filter is presented and compared experimentally with a classic Multichannel Wiener Filter in a noise reduction framework.