A paper from 2019 found that speaking with a louder voice creates more aerosolised viral particles [Asadi et al. 2019].
This simple Arduino project reminds people to not shout unnecessarily. It could be used in classrooms, meeting rooms or any other setting where people are talking.
The equipment list, instructions and code are available here: https://www.instructables.com/Voice-Loudness-Monitor-Arduino/
This project was supported by the University of Bristol and the Royal Academy of Engineering