618 



BELL SYSTEM TECHNICAL JOURNAL 



-I -2 -3 -4 -5 -6 -7 -8 -9 -10 -II -12 



W = LOGARITHMIC WEIGHT- FACTOR OF COMPOSITE NOISE 



Fig. 5 — Relation between total number of peaks per minute (iV) and the logarithmic 

 weight factor of composite noise (w). 



6 8 10 12 14 



DIFFERENCE BETWEEN NOISES IN DECIBELS 



Fig. 6 — Power addition of noises. 



