Sound Attenuation Ducts Walls

Overview

Engineering reference data for Sound Attenuation Ducts Walls in acoustics.

Key Formulas

Speed of Sound

$c = \sqrt{\gamma R T}$

Speed of sound in an ideal gas.

Sound Level

$L = 10 \log_{10}(I/I_0)$

Decibel level.

Wavelength

$\lambda = c / f$

Wavelength = speed / frequency.

Variables

Symbol	Description	Unit
$c$	Speed of sound	m/s
$L$	Sound level	dB
$\lambda$	Wavelength	m
$f$	Frequency	Hz

Sound Transmission Table

The following table provides typical sound transmission loss (TL) values through rectangular duct walls based on sheet metal thickness and frequency.

Duct Geometry Note

The acoustic performance of round and oval ducts is superior to that of rectangular ducts. Their curved surfaces allow less breakout noise, and they are particularly effective at containing low-frequency sound.

Interactive Charts

References

• Original Source