NorFLAG 4.0 – Acoustic Performance Estimation Software

New features v 4.0

  • Free use of NorRT60
  • Similar to the general model for a perforated plate with rectangular slots (or slits), the model for perforated plate with circular holes is exchanged with a general one covering all sizes of perforations, from micro-perforations to common large holes.
  • When predicting results for reverberation room measurements, a choice of the upward integration angle is now available.
  • The one-parameter model of porous material by Wilson is substituted by a newer one having three parameters: resistivity, the porosity and the tortuosity.
  • When calculating the attenuation in ducts the result is now selectable in dB/m or in dB specifying the length of the duct silencer.
  • And more…..


Do you need to estimate the acoustic performance of constructions combining different material layers such as porous materials (e.g. mineral wool), solid and perforated plates (slotted, with circular holes, microperforated)? NorFLAG does the job of calculating the absorption coefficient, the impedance and the sound reduction index for constructions combining such different material layers. NorFLAG also calculates the attenuation of noise in ducts, e.g. air-conditioning ducts, lined with the chosen layers.

Calculations may be performed at single frequencies or as mean values in one-third-octave bands, for free and diffuse field sound incidence. For exported data (MS-Excel or ASCII) values in octave-bands are presented. One may estimate the absorption coefficient measured in a standard reverberation room according to ISO 354. These absorption coefficients may be directly exported to the software NorRT60 (former WinRT60) that calculates the reverberation time in rooms. In version 4, the NorRT60 comes free of charge with the NorFlag license.

For more information NorFLAG 4.0 please see pdf.

Manual for NorFlag, version 4.0

How to buy

The NorFLAG software is only available for purchase through this website. Simply download the software from the link below. Unpack the .zip file, and follow the instructions found in readme.txt.

You are then entitled a 7 days’ free trial period. Thereafter, a registration code will appear. This code must be sent to orders@norsonic.comfor re-coding to a permanent license Key. To avoid operational break after 7 days please fill in form below to receive ordering details. If more than 5 licenses are required, please contact for a quotation.

Please note:
NorFLAG is offered as a single user license only. A purchased license key is valid only for the installation on the PC that generated the registration code. Moving a purchased license to another PC is not possible without ordering a Moving/Lost license fee. If your PC crashes you also have to order a Moving/Lost license fee to install a new license on a new PC

Download NorFlag sofware