Strutt|Criteria|Curves|Sound Level|NCB inserts the Balanced Noise Criterion (NCB) curve into the current row of the worksheet.
The user may select which NCB curve to display by entering the curve number into Column D.
The NCB curve is intended as an improvement of the base NC curve to improve its subjectively 'rumbly' and 'hissy' characteristics at low-frequency and high-frequency.
Note that the NCB method has been replaced by the RNC method in the latest (2008) revision of S12.2. NCB is included in Strutt for completeness.