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

Figure 3

Transmission loss of aluminium perforated plates having thickness 𝑡=1mm with (a)-(b) micro size holes and (c)-(d) medium size holes subjected to normal incidence of sound: (a) 𝜎=1.5%, (b) 𝑑_𝑜=0.1mm, (c) 𝜎=1.5%, and (d) 𝑑_𝑜=2mm.

(a)

(b)

(c)

(d)