Understanding acoustic performance of open plan and single cell classrooms in New Zealand primary schools

Abstract

Open-plan learning environments are being re-introduced into New Zealand primary schools. They are often today referred to as ‘Modern’ Learning Environments (MLEs). The ‘modern’ space is designed to provide flexibility and the ability to facilitate two or more classes into one. This paper reports on and tests the development of a case study methodology for evaluating the effect of acoustic performance on students in MLEs and single cell classrooms in New Zealand primary schools. The purpose of this study is to develop a method for testing the acoustic conditions in open-plan and single cell classrooms, and to gain an evidencebased understanding of the acoustic issues encountered in these new, and acoustically very different, MLEs. MLEs traditionally have fewer walls, more glass to enable visual contact between teachers and students, a larger floor area, and an increase in student and teacher numbers in a single space (Ministry of Education, 2016). It seems they are being introduced in an attempt to match the physical provision of space to the collaborative teaching methods being used in modern schools. Perception of speech has been shown to influence a child’s ability to learn and understand instructions. Hearing comprehension is affected by reverberation and noise- to- source ratio at the child, which is influenced by the characteristics and materiality of a space (Shield, Greenland, & Dockrell, 2010). Most international research on the acoustics of classrooms has focused on traditional single cell classrooms. Classrooms for the case studies were chosen based on teacher management, teaching methods, student age and classroom configuration (low ceiling, high ceiling, MLEs, single cell classrooms). A cross-case analysis is achieved through the relevant case study data coming from multiple sources of evidence because each case study tests subjective assessment and behaviour observation in addition to the acoustic measurements, reverberation time and signal-to-noise ratio are the recommended acoustic measurements performed in each classroom. The reverberation time (RT) results enable a comparison between actual performance and the acoustic design guidelines for schools. The signal-to-noise ratio measurements test scenarios that the literature suggests could be problematic acoustically in MLE classrooms. The subjective assessment of student and teacher perception of the acoustic quality and comfort uses a classroom mapping exercise and a teacher interview, which are based on questionnaires from previous case studies on noise sources heard and annoyance from noise inside the classroom. The results show some differences between the tested MLE and single cell classrooms. Audio recording results show teachers in MLE classrooms are speaking louder than teachers in single cell classrooms. Apart from one outlying classroom, all classrooms tested had similar audio recording noise levels and noise levels dropping over the distance of the classroom. The proximity of the tascam audio recorders to absorbent materials influenced the audio recording levels the most. The student mapping exercise results complemented the audio recordings results; where the students had marked an area as being ‘quiet’ the audio recordings showed lower levels and less dynamic range. It was noted through in-class observation that there is more distraction of students in MLE classrooms by other class bases, and interference of audio noise when more than one class base is participating in a noisy activity, however, this can also happen in single cell classrooms. It was also noted that teacher management and structure of the class impacted on the noise levels within MLE classrooms more than single cell classrooms. This is because students and teachers in MLE classrooms are influenced by the activities and subject adjacent class bases are engaging in throughout a school day. Eight out of ten classrooms met the recommended standard for reverberation time in New Zealand primary schools and the classrooms with acoustic ceiling tiles performed with a lower RT average. This study found differences in acoustic and subjective results between MLE and single cell, along with differences between types of configurations and materials used in areas of the classroom. The results have enabled a better understanding of the acoustic spaces MLE and single cell classroom offer. Ten classrooms have been tested in this research; they have been chosen to represent different types of primary school classrooms in New Zealand.