Improved acoustics can lower stress and crying in preschool children

When children are dropped off at a school or day care for the first time, there can be a lot of feelings and sometimes meltdowns caused by being separated from parents, meeting new people, and hearing new noises. Could the architecture of the room help to soothe at least some of the children's concerns?

Classrooms without any sound absorption are the majority in Japan. My motivation was to make people aware of the importance of acoustics in classrooms because in Japan, there are no standards or guidelines for acoustic design of preschool and school classrooms."

Ikuri Matsuoka, a master's student at Kumamoto University, Japan

Children in the process of developing language and speech can have a hard time listening, and so a classroom with lots of noise and reverberation can disturb communication and cause them to talk louder.

"We expect that preschool children entering school for the first time normally feel stressed by the difficulty of verbal communication," Matsuoka said. "Therefore, this study examined whether sound absorption could mitigate such adverse effects."

To test the effect of sound absorption on children's noise, Matsuoka installed polyester fiberboard, a type of sound-absorbing material, onto one classroom's ceiling and compared it to another without any.

Matsuoka will present their findings Friday, May 23, at 1:40 p.m. CT as part of the joint 188th Meeting of the Acoustical Society of America and 25th International Congress on Acoustics, running May 18-23.

Matsuoka analyzed the indoor activities using video and audio to determine noise levels and the number of times the children cried. After six months, Matsuoka found that children were louder in the room without the insulation.

"During the experiment, I interviewed the four teachers in the four classes several times," Matsuoka said. "Three of the four teachers answered that they felt the reverberation had changed, and one of them, a veteran teacher with 25 years of experience, answered that she felt clearly more comfortable talking to the children."

To complement their results, Matsuoka and their professor also used artificial intelligence and machine learning to analyze the data automatically. They used an acoustic event detection method to identify children's crying instead of manually scrubbing through the data. This work will also be presented during a session on "Materials for Sound Absorption, Diffusion, and Transmission Loss" on Friday, May 23, at 1:00 p.m. CT.

"We expect that machine learning will be necessary for long-term observations," Matsuoka said. "From our research, we hope that those involved in both the child care and architectural fields recognize how important it is to have reduced reverberation that mitigate noisy atmosphere and promote clear verbal communication for children."