Optimizing classroom acoustics using computer model studies

Speech intelligibility in rooms is determined by both room acoustics characteristics as well as speech-to-noiseratios. These two types of effects are combined in measures such as useful-to-detrimental sound ratios whichare directly related to speech intelligibility. This paper reports investigations of optimum acoustical conditionsfor classrooms using the ODEON room acoustics computer model. By determining conditions that relate tomaximum useful-to-detrimental sound ratios, optimum conditions for speech are determined. The results showthat an optimum mid-frequency reverberation time for a classroom is approximately 0.5 s, but speechintelligibility is not very sensitive to small deviations from this optimum. Speech intelligibility is influencedmore strongly by ambient noise levels. The optimum location of sound absorbing material was found to be onthe upper parts of the walls.L'intelligibilit\ue9 de la parole dans une chambre est d\ue9termin\ue9e par les caract\ue9rsitiques acoustiques et aussi parles rapports parole-bruit. Ces deux types d'effets sont combin\ue9s dans des mesures comme des rapports sonutile/son-nuisible, qui sont reli\ue9s directement a l'intelligibilit\ue9 de la parole. Cet article pr\ue9sente lesinvestigations des conditions acoustiques optimums pour des classes en utilisant le mod\ue8le g\ue9n\ue9r\ue9 par laprogramme acoustique ODEON. En d\ue9terminant les conditions reli\ue9es aux rapports son-utile/son-nuisiblemaximums, il est possible de trouver des conditions optimums pour la parole. Les r\ue9sultats montrent qu'untemps de r\ue9verberation mi-fr\ue9quence optimum pour une classe est environ 0.5 s, mais I'intelligibilit\ue9 de laparole n'est pas tr\ue8s susceptible aux petites d\ue9viations de cet optimum. L'intelligibilit\ue9 de la parole estinfluenc\ue9e plus fortement par les niveaux de bruit ambiant. On trouve que la location optimum de mat\ue9rielabsorbant est sur la partie sup\ue9rieure des murs.Peer reviewed: YesNRC publication: Ye