Classroom (<100 m²)
Classrooms are the most common type of room in a school building and the location for not only desk-bound teaching, but group work and individual study. Hearing and seeing well is crucial to the learning process and good speech intelligibility is a must. The room has to promote intellectual work and concentration.
Reverberation time of 0.5 seconds or less. To achieve this, an acoustic ceiling of sound absorption class A (in accordance with EN ISO 11654) covering 85% of the ceiling surface is needed. The rear wall should also be fitted with a wall absorber of sound absorption class A.
Increased absorption at 125 Hz may be required, particularly for listeners and speakers with impaired vision or hearing. For good speaker comfort, add a reflector over the teacher's desk area.
At the back: Ecophon Wall Panel/Super G 0.8 to 2.0 m above the floor
The ceiling: Ecophon Master/alpha + Master Extra Bass
Above the teacher: Ecophon Master/gamma (reflector)
Building codes and standards
UK regulations, Building Bulletin 93 (BB93), states that primary school classrooms must achieve an unoccupied mid frequency (Tmf) reverberation time of <0.6 seconds. In secondary schools it states that an unoccupied mid frequency (Tmf) reverberation time of <0.8 seconds be achieved. If the classroom is designed specifically for the teaching of hearing impaired pupils then an unoccupied mid frequency (Tmf) reverberation time of <0.4 seconds is required.
Swedish Standard 02 52 68 recommends a reverberation time of 0.5 or 0.6 seconds, depending on the selected quality level. This applies to normally furnished but unoccupied rooms. The above figure is the highest recommended value for the frequency range 250 - 4,000 Hz. At 125 Hz a value 20% higher is permitted.