Based on a programme of research examining classroom acoustics and children’s perceptions and learning an evaluation of the installation and use of sound amplification systems in mainstream and special schools in England has been carried out. The evaluation included noise surveys of classrooms, a questionnaire survey of pupils and teachers and experimental testing of children in with and without the use of sound amplification.  The aim of this project was to investigate the impact of classroom modifications on teaching and learning in elementary school classrooms. Barriers to teachers’ use of sound amplification were found in terms of equipment placement and maintenance, appropriate training and teachers’ knowledge. Teachers’ and pupils’ perceptions are compared with objective data evaluating change in performance when amplification is used for language and cognitive tasks. Data from children with hearing impairments and additional learning needs are analysed for comparative purposes. The results are discussed in terms of effective learning and listening environments in elementary schools.