A pilot study in primary school on the effect of noise monitoring system with lighting feedback on teachers’ voice parameter, noise levels and subjective assessments

Teachers’ vocal behaviour is affected, among other aspects, by the noise generated by pupils that talk and move in classroom. Under noisy conditions, teachers are likely to increase their voice level causing possible negative consequences on their vocal health. In this pilot study a noise monitoring system with a lighting feedback, namely the SEM (Speech and Sound SEMaphore) device, has been used as an educational tool. It encourages pupils to reduce their voice volumes through a coloured lighting feedback. Seven teachers from four classes of a primary school in Turin (Italy) have been monitored over two to four working days with SEM switched on and off. The results have shown that the background noise level averagely decreased by about 2.9 dBA when SEM was switched on. With SEM switched off, a tendency towards Lombard effect has occurred, i.e. an increase in the speech level with background noise level at a rate of about 0.4 dB/dB. Conversely, such effect has not been found with SEM switched on. Self-reported impressions of teachers indicated that SEM effectively reduces vocal effort and improves speech intelligibility in the classroom.