Environmental noise is a growing priority. Concerns about avi at ion noise have essentially halted airport expansion in large metropolitan areas, which has increased congestion, reduced safety margins, and impacted economic development. Community response to highway traffic noise is beginning to cre at e the same conflict between economic development, safety, and environmental concerns for ground transport at ion systems. Environmental noise is a complex systems problem with significant sociological, physiological, or policy elements as well as engineering issues. Thus, environmental noise is not exclusively an engineering problem. However, engineering research is essential to the mitig at ion aspect of this issue and in some cases to the effects aspect as well. Engineering researchers make good partners and leaders of the multi-disciplinary teams th at are required to find balanced solutions. Examples of the evolution of multi-disciplinary research teams for traffic noise and avi at ion noise will be described with particular emphasis on the engineering research components of these problems.