A field study was made of the acoustical environment of schools designed for increased flexibility to meet the spatial requirements of new teaching methods. The object of the study was to define all the criteria for the acoustical design of this type of classroom including the determination of--(1) minimum acoustical separation required for effective group and individual work, (2) tolerable sound levels, and (3) objectional types of sounds. The resulting data was intended as a guide for architects, engineers, acoustical consultants, and educators. Questionnaires dealing with the aural environment of their schools were sent to teachers in thirty-seven schools in all parts of the country. Teams of acoustical consultants then analyzed each school to accurately determine noise reduction, reverberation, speech interference level and articulation index. The collected data, discussion, and conclusions are presented for each school studied. This document previously announced as ED 014 206. (JT)