Improvement of sound transmission through partitions for protection against infection by adding resonators

In Japan, after the COVID-19 outbreak, people sometimes have conversations separated by a transparent partition for infection control. However, the partition makes communication difficult because it reduces the sound transmission. Thus, we have proposed improving sound transmission by attaching resonators consisting of a perforated plate to the surface of the partition, thereby creating a multi-layer structure for low-frequency resonance transmission. In this study, considering the reflection from the tabletop, diffraction from the edge of the partition, and transmission through the partition, we theoretically calculated the sound pressure level on the other side of the partition. As a result, when using a partition with a height of 600 mm, a width of 900 mm, and a thickness of 5 mm, it was predicted to improve the level by 10 dB at 800 Hz by attaching the relators on both sides of the partition. Moreover, the estimated results were verified by measuring the sound pressure level through the partition put on the floor in the semi-anechoic chamber. In comparison between them, the increase in sound pressure level measured was greater than the estimated one. Therefore, this method makes conversation easier.