To calculate specific loudness in Simcenter Testlab, do the following:
1. Turn on “Signature Throughput Processing” under “Tools -> Add-ins”. This allows calculation of a specific loudness spectrum using narrowband data. If loudness based on filters is desired, also turn on “ANSI-IEC Octave Filtering”.
2. In Signature Throughput Processing, set the tracking type to “Stationary” under the “Acquisition Parameters”. By entering a very large number of averages, it can be ensured that the entire time history is processed. The software will automatically process what it can from the time history and then stop.
3. In the “Section Settings”, find the “Psychoacoustic Metrics” tab and turn on the “Specific Loudness ISO 532B DF Map” or “Specific Loudness ISO 532B FF Map”. Based on the environment the measurement was taken in, select DF for Diffuse Field and FF for Free Field.
4. Press “Calculate”. You could get some warnings if the spectral resolution or number of octave bands is not ideal. If wanting to calculate the specific loudness anyway, press OK.
5. The specific loudness spectrum can be viewed in the Navigator.