System-Level Power Optimization of Digital Audio Back End for Hearing Aids

Abstract

Abstract:Abstract-This work deals with power optimization of the audio processing back end for hearing aids -the interpolation filter (IF), the sigma-delta (SD modulator and the Class D power amplifier (PA) as a whole. Specifications are derived and insight into the tradeoffs involved is used to optimize the interpolation filter and the SD modulator on the system level so that the switching frequency of the Class D PA -the main power consumer in the back end -is minimized. A figure-of-merit (FOM) which allows judging the power consumption of the digital part of the back end early in the design process is used to track the hardware and power demands as the tradeoffs of the system level parameters are investigated. The result is the digital part of the back end optimized with respect to power which provides audio performance comparable to state-of-theart. A combination of system level parameters leading to the lowest switching frequency of the Class D power amplifier reported in literature for the SD modulatorbased back end is derived using this approach. Response to Reviewers:This submission is the final version of our manuscript. According to the instructions for authors and the email from the editor the following changes were done: -the order of the refernces was changed to alphabetic order.-footnote with contact information of all authors was added on the first page Thank you. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationPeter Pracný, Abstract-This work deals with power optimization of the audio processing back end for hearing aids -the interpolation filter (IF), the sigma-delta ( modulator and the Class D power amplifier (PA) as a whole. Specifications are derived and insight into the tradeoffs involved is used to optimize the interpolation filter and the  modulator on the system level so that the switching frequency of the Class D PA -the main power consumer in the back end -is minimized. A figure-of-merit (FOM) which allows judging the power consumption of the digital part of the back end early in the design process is used to track the hardware and power demands as the tradeoffs of the system level parameters are investigated. The result is the digital part of the back end optimized with respect to power which provides audio performance comparable to state-of-the-art. A combination of system level parameters leading to the lowest switching frequency of the Class D power amplifier reported in literature for the  modulator-based back end is derived using this approach.