Microphone Array Signal Processing and Active Noise Control for the In-Helmet Speech Communication

For in-helmet voice communication, the currently used Communication-Cap-based Audio (CCA) systems have a number of recognized logistical issues and inconveniences that cannot be resolved with incremental improvements to the basic design of the CCA systems. The objective of this research project is to develop an Integrated Spacesuit Audio (ISA) system that can possess similar performance to a CCA while offering users inherent comfort and ease of use. In Phase I, the feasibility of using microphone array beamforming or multichannel noise reduction plus a single-channel postfilter to combat a variety of types of in-helmet noise was validated. Comparative simulations indicated that novel multichannel noise reduction is more practical and more effective than traditional microphone array beamforming for ISA systems. Phase II will pursue advanced development and prototype of the proposed technical solution for the ISA system. Directions for improvement that were established in Phase I will be carefully followed, subjective evaluation will be carried out, and the ISA designs will be further optimized. Finally a real-time demo system will be built using either DSP or FPGA. It should be ready for testing and use by NASA at the end of Phase II.