Design of Low Complexity Adjustable Filter Bank for Personalized Hearing Aid Solutions

The emerging demand for personalized hearing aids requires the filter bank of a hearing aid system to be capable of decomposing the sound waves in accordance with the characteristic of the patient´s hearing loss. In this paper, an efficient adjustable filter bank is proposed to achieve this goal. By careful design, the number of the subbands as well as the location of the subbands can be easily adjusted by changing a 4-bit control signal. The proposed filter bank has extremely low complexity due to the adoption of fractional interpolation and the technique of symmetric and complementary filters. Only one prototype filter is needed for each of the stages, the multiple passbands generation stage and masking stage. We show, by means of examples, that the proposed filter bank can meet different needs of hearing loss cases with acceptable delay.