ARTICULATION TESTING METHODS 



823 



practice effects for several types of distortion for a crew of eight people. 

 All six of the circuits were tested on each test before going on to the 

 following test. The first three tests were made successively and 

 covered a period of about two months. In each test the types of 

 distortion were interspersed. In other words half of the first test 

 was completed with the filters in one order, and the other half with 

 the filters in the reverse order. The fourth test was made about three 



20 40 60 80 20 40 60 80 100 



SYLLABLE ARTICULATION OBTAINED AT ONE TIME 



Fig. 4 — Practice effects 



months later, and the fifth test was made approximately six months 

 later. Although the crew had been testing various circuits for about 

 a year, and were thoroughly accustomed to the routine, these particular 

 circuits had not been previously tested, so that, the crew's experience 

 with these types of speech distortion was small. It is evident that 

 the articulation of an experienced crew reaches saturation very 

 quickly. It is probable that practice effects for a crew of several 

 years' experience with distorted speech would be negligible. 



