adults to hear equally well. As adults, teachers may not appreciate the additional problems that excessive noise creates for younger students.
Finding 6d: Excessive noise is typically a more significant problem than is too much reverberation in a classroom. It is not possible to have both increased speech level (to maximize signal to noise) and reduced reverberation times. Good acoustical design must be a compromise that strives to increase speech levels without introducing excessive reverberation.
Finding 6e: The most substantial body of research related to excessive noise and learning in the classroom addresses the impacts of road traffic, trains, and airport noise.
Finding 6f: Some available evidence indicates that teachers may be subject to voice impairment as a result of prolonged talking in noisy school environments. However, there is no information to quantify a relationship between specific noise levels in classrooms and potential voice impairment.
Recommendation 6a: To facilitate student learning, future green school guidelines should require that new schools be located away from areas of higher outdoor noise such as that from aircraft, trains, and road traffic.
Recommendation 6b: Future green school guidelines should specify acceptable acoustical conditions for classrooms and should require the appropriate design of HVAC systems, the design of walls and doors separating classrooms and corridors, and the acoustic quality of windows and walls adjoining the outdoors. This recommendation is most easily achieved by requiring that green schools comply with American National Standards Institute (ANSI) Standard 12.60, “Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools.”
Recommendation 6c: Additional research should be conducted to define optimum classroom reverberation times more precisely for children of various ages.