The Monterey Fire Department has experienced difficulty communicating clearly on emergency incidents with personnel wearing SCBA, particularly in the high noise environments associated with interior firefighting and other emergency activities. The problem is that the department has not formally evaluated or implemented any of the technological advances in SCBA communication systems and accessories specifically designed to improve voice communications for SCBA users. The purpose of this research project is to quantitatively evaluate the effectiveness of available SCBA voice communication systems in improving voice communications while wearing an SCBA under simulated emergency incident work conditions.A comprehensive literature review, evaluative research methodology, and questionnaire were used to answer the following research questions: (a) what types of technologies and voice communication systems are available for the various SCBA utilized in the fire service, (b) what standards, if any, apply to SCBA voice communication systems, (c) which of the available SCBA voice communication systems provide improved voice communications under simulated emergency incident conditions, and (d) which voice communication system, if any, is most effective fort he Monterey Fire Department? Results identify three general categories of SCBA communication systems that are governed by NFPA and ANSI standards.Test results also indicate the integrated speech diaphragm, voice amplification, and wireless radio interface systems were more effective than the hard-wired radio interface system in improving voice communication clarity under simulated emergency incident conditions. Questionnaire results further indicate that the wireless radio interface and voice amplification systems received higher satisfaction ratings from the subject evaluators than the speech diaphragm or hard-wired radio interface systems, suggesting that Monterey Fire Department personnel would prefer either of the former SCBA communication systems over the latter.