Speech intelligibility inside primary classrooms: a virtual reality laboratory test

Good design of school environments is, in part, responsible of the learning levels of pupils. It has influence both, on the comfort of occupants and on the efficiency of the communication process. Speech comprehension is the core of this process and assumes particularly relevance for the pupils of primary school, which have more difficulties to understand complex verbal messages and to keep high attention during listening. On the other hands, visual aspects are also important, as they can modulate the speech comprehension of talkers. The main tools available to designers (3d graphic software, and lighting and room acoustic's modelling software) allow, today, combined with those of Virtual Reality (game engines, virtual speaking characters) to investigate in deep on the effects of the audio and visual integration during the classes. This paper presents the preliminary results of a study that, using two Virtual Reality scenarios (Traditional and Innovative) with similar acoustic performances compare the speech intelligibility of a virtual talker, in different listening position of the virtual classroom and in different background noise conditions. Speech intelligibility scores was obtained using Diagnostic Rhyme Test (DRT) on primary school pupils and scores were correlated with the Signal Noise Ratio (SNR).