The objective of this project is to safely adapt a very efficient audio mechanical transducer (AMT) to standard hearing protection devices. This combination will then be used as a component in the development of the high noise environment communications systems. The AMT Communications System is specifically designed to reduce the problems associated with communications in high noise environments. The system will require the use of adequate and operating hearing protection to function. Therefore, the environment of the worker will be enhanced, emergency and warning signals will be heard, and hearing protection programs will have better acceptance. The benefit to management will be increased productivity, worker safety and greater compliance with hearing protection programs. The AMT Communications System is a potential benefit to 11,000,000 workers. Phase 1 developed and tested the basic components of the AMT Communications System. Phase 2 will establish the safety of the system, build on the Phase 1 development and begin the speech intelligibility studies. Phase 3 will design and build the electronics of the system, prototype and test five different communications systems, and investigate the impact of communication in high noise environments on management and the workers. In addition to the AMI Communications System, long term benefits include advanced knowledge of speech intelligibility and a computer modeling of circumaural hearing protectors.