This proposal addresses two major problems associated with state-of-the-art hearing aids: lack of phase/directionality and how directional hearing aids can utilize micro-machined and MEMS based microphones and loudspeakers for higher reliability and ease of operation. The proposal addresses integration and application of multi-phase/multi-microphone directional hearing aids with on-chip MEMS microphones. This will reduce the microphone size and spacing, use new signal processing methods for phase/directionality for the digital hearing aid, extend battery-life, and will reduce size. Another major benefit will be improved noise suppression and directionality by utilizing nano-scale devices and adaptive mixed-signal microelectronics. This proposal is aimed at developing new university-industry collaborative research on ultra-low power multi-phase digital hearing aid systems on a chip. The proposal targets high-risk/high-gain research focused at the fundamental issues facing micro/nano Ics, MEMS, and signal processing for multi-phase array digital hearing aids. The long term road map for this project has the strong potential to impact many research areas that are not being carried out by industry. The synergetic nature of this research will enable new developments for an innovative collaborative industry-university educational program as well as the direct transfer of fundamentally new science and technology between university and industry. From the technology perspective, this project will lead to new ultra-low power micro-level audio transceivers on a chip for the digital hearing aid with aggressive goals to reduce the size and power.