[unreadable] DESCRIPTION (provided by applicant): The continued research and development of a portable, inexpensive, system for ambient noise attenuation is proposed for use in audiometric testing. The device will be a technologically advanced headset used in conjunction with insert earphones. In combination, the total attenuation of the device will be superior to any current portable alternative. This combination of headset and insert earphones will be designed to attenuate ambient acoustic noise during audiometric testing, and will replace sound isolation test rooms and mobile test facilities under certain ambient noise conditions. The portability of the system will enable it to be used in venues such as schools, nursing homes, prisons, and industrial plants. The result of this research will be tested pre-production units. The ultimate goal of this research and development will be to manufacture a portable audiometric testing system that provides noise-attenuation properties superior to a single-walled room in meeting ANSI S3.1-1 999 standards.