Normal Incidence of Sound Transmission Loss from Perforated Plates with Micro and Macro Size Holes

Figure 9

Measured sound transmission loss (left column) and effect of perforation (right column) of plates with micro size holes: (a) 𝑑_𝑜=0.3mm, 𝜎=0.5%, (b) 𝑑_𝑜=0.5mm, 𝜎=0.5%, and (c) 𝑑_𝑜=0.5mm, 𝜎=1.5%.

(a)

(b)

(c)

(d)

(e)

(f)