LOUDNESS 



395 



-20 -10 



20 30 40 50 60 70 80 90 100 110 120 



INTENSITY LEVEL-DB 



-20 -10 



,0 20 30 40 50 60~~70 80 90 100 HO 120 



INTENSITY LEVEL-DB 



Fig. 5 (A and B)— Loudness levels of pure tones. 



