Normal Incidence of Sound Transmission Loss of a Double-Leaf Partition Inserted with a Microperforated Panel

Figure 5

Comparison of sound transmission loss of DL (—) with that of DL-MPP for different perforation ratios (𝑙=0.1𝐷, 𝑑_𝑜=0.1 mm, 𝐷=100 mm; – – 𝜎=0.5%, – · – 𝜎=1.0%, and ··· 𝜎=1.5%).