The purpose of this article is to describe the use of impulse response measures and observations in Florida classrooms. As a result of measures and observations in "healthy" and poor acoustical environments, 10 practical recommendations are proposed for improving the acoustical environment in schools. The primary research for these recommendations consisted of recording acoustical measurements of reverberation time and background noise, as well as newer acoustical measurements based on impulse response techniques, in 56 actual classrooms. Observations of classroom situations occurred in a subset of these schools. Computer and physical models of eight classrooms were constructed and tested with varying room finish materials and background noise levels to study the comeverberation bined effects of these architectural items on speech perception in the model rooms. The primary recommendations all relate to school design and planning. These include air-conditioning system selection and noise control techniques to minimize interference with listening, interior classroom acoustical design principles for maximizing speech perception, and the documentation of teaching methods and classroom arrangements that result in improving speech intelligibility and other factors affecting speech perception.