Strutt|Criteria|Curves|Sound Level|Fletcher Munson ISO226 (Random Noise) inserts the equal-loudness curve for random noise into the current row of the workbook. The user may enter the phon value of the curve (i.e. the 1 kHz value) into Column D.
Entering 'MAF' into Column D returns the Minimum Audible Field (approximately 4.2 phon)
Reference: ISO226 (2003) Acoustics - Normal equal-loudness level contours