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BELL SYSTEM TECHNICAL JOURNAL 



distortion, but rather to show the relative importance of the various 

 factors for particular cases. In these cases the time factor appeared to 

 be the one of most importance. 



Fig. 7 — Articulation vs. delay distortion. 



It is evident that the primary effect of phase distortion was to effec- 

 tively narrow the transmitted frequency range. The phase distortion 



0.014 



0.012 



0.002 



1,000 2,000 3,000 4,000 5,000 



FREaUENCY IN CYCLES PER SECOND 



6,000 



Fig. 8 — Articulation and delay distortion for a 5000 cycle low pass filter. 



caused by the twenty-five sections of the all pass network associated 

 with a 2400 cycle low pass filter reduced the articulation from 92.7 per 

 cent to approximately 89 per cent. Reference to Fig. 3 shows that 



