Sound Insulation

On site measurement of the impact-noise insulation L'n, L'nT

The standardized impact-sound pressure levels L'n and L'nT define on site the ceiling sound reduction capacity.

The calculation is carried out by comparing the receiving room average sound spectrum (after considering background noise effects) when the impact-noise machine is operating in the source room. The receiving room average reverberation time (will give L'nT) or equivalent absorption area (will give L'n) can be used as calculation correction factor.

Procedure

Perform the reverberation time measurements

Perform the average reverberation time and the equivalent absorption area calculation

Perform the measurements of single average spectra in average mode

Download the data files into a PC folder.

Click on the Start Analysis button (or select the menu item Analyze -> SOUND INSULATION -> Start).

In the window that opens, select the Impact noise insulation on site (L'n - L'nT) measurement and click OK to confirm.

You should create a new project containing all files concerning the processing or open an existing one.

Create the project "Lp_index"

This opens the Impact noise insulation on site (L'n - L'nT) main window.

The window is divided into four sections:

Receiving room spectrum: it describes the signal average spectrum measured in the receiving room when the impact-noise machine is operating.

Receiving room noise: it describes the background noise average spectrum measured in the receiving room in absence of the impact-noise machine.

Correction factor: it uses the data of the receiving room average reverberation time (the standardized impact-sound pressure level coefficient L'nT is calculated) or equivalent absorption area (the standardized impact-sound pressure level coefficient L'n is calculated).

Pressing Open File, opens the data files (dl5 extension) concerning the previously acquired and saved on PC receiving room spectrum measurements.