Arianna Astolfi

ABSTRACT

A minimum measurement protocol for assessing classroom acoustics and its effect students’ learning processes

The new Italian standard UNI 11532-2 includes the main descriptors related to noise, room acoustics and speech intelligibility to be considered for the design and verification phases in the case of classrooms and other school environments.
In the standard, Clarity C50 has been included as speech intelligibility index for classrooms with volume lower than 250 m3. C50 is an easy-to-measure index which is also correlated with the reading abilities of primary school children. Further, its centre-classroom value has been found comparable with the average value measured across many positions in the classroom and it is strongly related to the more complete speech intelligibility index Useful to-detrimental-energy ratio, U50. In this work, the measurement protocol described in the UNI standard is presented, together with the target values of the main acoustical parameters. Besides, statistics on the measurements carried out in more than 20 classrooms in Italy are compared and a selection of a minimum set of objective parameters to be used for the acoustical characterisation of classrooms together with a minimum measurement protocol, is proposed.