Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Sound Transmission through Duct Walls

Estimating sound transmission from ducts to surrounding rooms

Sponsored Links

Sound transmission through duct walls

Sound or noise transmitted from the inside of a duct to the surrounding room can be expressed as:

Lp = LN - TL - 10 log (A F / 4 Ad)                                 (1)


Lp = sound pressure in room (dB)

LN = sound power level in the duct (dB)

TL = transmission loss through duct wall (dB)

A = room absorption (m2 sabine)

F = cross section area of duct (m2)

Ad = surface area of duct (m2)

Typical sound transmission loss through duct walls are indicated in the table below:

Attenuation - TL - (dB)
Duct sheet
Frequency (Hz)
1.25 17 22 25 29
1.0 15 20 23 27
0.75 14 19 22 26
0.65 12 17 20 24
Sponsored Links

Related Topics

Related Documents

Tag Search

  • en: sound transmission duct wall
Sponsored Links

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

Translate this page to
About the Engineering ToolBox!


This page can be cited as

  • Engineering ToolBox, (2003). Sound Transmission through Duct Walls. [online] Available at: [Accessed Day Mo. Year].

Modify access date.

Customize Ads in the ToolBox

Make ads more useful in Google Ad Settings .

. .


3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

11 16

Sponsored Links