Official Journal of the Japan Wood Research Society
Table 1 The average sound absorption coefficient at four frequency sections and NRCs of pine cone particle sound absorbers
From: Investigation of sound absorption capability of pine (Pinus densiflora) cone particles
Thickness (cm) | Average sound absorption coefficient | NRC | |||
|---|---|---|---|---|---|
250–500 Hz | 500–1000 Hz | 1000–2000 Hz | 2000–6400 Hz | ||
4 | 0.183 | 0.323 | 0.959 | 0.695 | 0.540 |
6 | 0.182 | 0.526 | 0.881 | 0.755 | 0.586 |
8 | 0.377 | 0.982 | 0.646 | 0.998 | 0.751 |
10 | 0.645 | 0.868 | 0.693 | 0.812 | 0.755 |