The low value of the weighted apparent sound reduction index Rw 0 ¼ 17 dB contributes significantly to the noise transmission from one room to the other, contributing to the elevated levels of background noise inside the classrooms. The required sound reduction index between a classroom and corridor in other countries such as Germany is Rw 0 ¼ 52 dB (Bobran, 1995). The recommendation of the Building Bulletin 93—‘‘Acoustic Design of Schools’’, from United Kingdom (BB93, 2003), is a value of Rw 0 ¼ 55 dB for the airborne sound insulation between corridor and primary/secondary classroom. In Brazil there is no legislation for sound insulation with respect to exterior noise for classrooms and for the internal sound insulation upon room function.