Qualidade sonora em sala de aula: estudo de soluções de condicionamento acústico para manual referencial das escolas da rede pública estadual do Rio Grande do Norte

Abstract

Classrooms are the main space for exchanging and building knowledge. As speech is the most used instrument for these purposes, its adequate understanding is essential. Speech intelligibility in classrooms depends on environmental acoustic conditioning factors – however, controlling this conditioning depends on specific knowledge and tools. The Education Secretariat of the Government of Rio Grande do Norte, in an attempt to guarantee quality for the schools under its administration, is developing a manual of “Reference Standards for School Operations”, which includes elements of environmental comfort. This manual does not, however, include instructions for acoustic conditioning of school environments. This dissertation seeks to contribute to this manual through the general objective of developing and analyzing architectural solutions for acoustic comfort to support classroom projects in state public schools in Rio Grande do Norte. Analyzing parameters of reverberation time (T30), initial decay time (EDT), speech transmission index (STI) and definition (D50), for classrooms in 3 schools in the state network, different solution models were constructed for each reality, combining flat and inclined ceilings with different proportions of acoustic material area. With reference values supported by recent research, these simulations were carried out to provide a range of possible absorption coefficient values for the material to be applied in each solution. The simulated results for each of the ceiling configurations in all classrooms were analyzed. Based on this, a step-by-step procedure was proposed to be incorporated into the State Government's Reference Standards manual, which includes lining solutions and simulated values. The research found that all classrooms had acoustic parameter values outside the recommendations. It was also found that most proposed ceilings present wide values of difference between maximum and minimum absorption coefficients, enabling a variety of acoustic material choices. A disparity was found between the reference values of T30, EDT, STI and D50, with the STI values being considerably more restrictive than the others.