APPLICATION OF ARTICULATION TESTING 357 



number of practice runs naturally depends, however, on the circuits 

 being tested. Unless the engineer in charge receives the data promptly, 

 the number of tests made may be insufficient or more than necessary. 

 In either case the successful completion of the program is delayed. 



The equipment used to analyze the data will be described in some 

 detail later in this paper, but its operating principles briefly are as 

 follows: A perforated tape, which is used with a standard printing 

 telegraph tape sender, performs, under the control of the master 

 timing commutator, two functions. It causes the syllable to be called 

 to appear visually before the caller (Fig. 1) at regular intervals and it 

 controls a relay system associated with four keyboards provided for 

 the observers (Fig. 2). The observers, on hearing the syllable, 

 press successively the keys labelled with the sounds which they 

 believe were called. If the correct keys are pressed a certain set of 

 relays operates; if the wrong keys are pressed another set operates. 

 The operation of the relays in turn controls a standard page printer 

 which types in succession the number of errors made on each sound. 



100-310-321-ni-30C-A01-OA2-l 11-201-1 12-A10-010-300-000-001 -110-401-000- 

 303-311-000-010-200-100-003-313-200-103-001-101-320-001-102-303-013-402- 

 302-003-001 -102-102-400-001 -010-304-1 10-1 12-101 -200-1 30-000-31 3-202-103- 

 301-301-411-000-002-001-201-211-104-001-402-011- 



M« 450 B1S-1-50-2-50-3-5C-4-46 T3 N4G.0 S70.1 



403-400-204-310-404-111-000-401-101-321-101-203-323-203-004-200-204-112- 

 001-131-310-002-332-221-402-001-312-111-403-301-203-213-401-001-410-443- 

 303-403-422-001-202-002-102-400-304-422-200-104-313-433-301-311-410-104- 

 201-324-440-321-300-100-304-301-001-413-004-320- 



MCD 451 A19-1-83-2-67-3-93-4-74 T3 N44.1 S58.S 



Fig. 3 — Record of articulation test as made by page printer. 



A typical typed record may be seen in Fig. 3. Each set of three 

 figures refers to a syllable. The first digit of the first number, 100, 

 shows that on the first syllable called in this list one observer mistook 

 the initial consonant, while the other three observers recorded it cor- 

 rectly. The second and third digits indicate that no errors were made 

 on the two succeeding sounds. The third number, 321, shows that 

 three observers missed the initial consonant, two missed the vowel and 

 one missed the final consonant. 



Under the control of the timing commutator this procedure of flash- 

 ing a syllable which is spoken by the caller, heard and acted upon by 

 the observers, whose opinion is analyzed and recorded upon the page 

 printer, goes on until the list of 66 syllables has been called. Imme- 



