The document discusses the importance of good acoustics in classrooms. It notes that students spend a significant portion of their time listening in the classroom. Poor acoustics, like excessive noise or reverberation, make it difficult for students to understand speech. It reviews research showing many classrooms have poor acoustics that exceed recommended noise limits and do not adequately control reverberation. The use of soundfield amplification systems in classrooms is shown to improve listening conditions and benefit both students and teachers.

6. Hitting a barrier

8. Reverberating environments

11. 28% 48% 0 52% 71% +6 60% words correct 83% words correct +12 .04 Hard of Hearing Normal S/N RT in sec

12. 11% 30% 0 28% 54% +6 41% 70% +12 1.2 Hard of hearing Normal hearing S/N RT in sec

19. How to reduce noise

31. http://www.mcsquared.com/classrooms.htm