810 BELL SYSTEM TECHNICAL JOURNAL 



New Standard Articulation Lists 



In setting up any testing list it is necessary to classify and select a 

 representative group of speech sounds. The National Phonetic 

 Association uses a basic alphabet of 65 different sounds and also uses 

 numerous modifiers which serve to distinguish slight variations in a 

 given sound. Such a system is too complex for testing purposes. 

 The revised scientific alphabet uses 48 simple sounds of which 24 are 

 consonants, 19 vowels, and 5 diphthongs. Besides these fundamental 

 sounds, connected speech contains certain recurrent combinations of 

 them, such as st, ing, etc. 



In speech these fundamental sounds are combined into syllables in 

 a large variety of ways, but as mentioned before, in constructing a 

 testing list it is desirable to adhere to very simple syllable forms. 

 More complex forms which include the compound endings are either 

 too few in number or involve unusual speech sound combinations. 

 In either case they are soon memorized by a testing crew working with 

 such lists. In the new lists, therefore, simplifications are made by 

 omitting the con-vow and vow-con types of syllables, leaving only 

 the con-vow-con type. In order to make syllables of this type it is 

 obviously necessary to have the same number of vowels and conso- 

 nants, provided that each consonant may be used in both the initial 

 and the final position. Some consonants, however, can be used only 

 in the former while others can be used only in the latter position. 



With these facts in mind the sounds that are shown in Table I were 

 adopted for these new lists. It will be noticed that all of the conso- 

 nants are used in both the initial and final positions in the syllable, 

 except h, w, and y, which are used only in the former, and zh, ng, 

 and st, which are used only in the latter position. As was the case 

 in the old standard lists, it will be seen that, in the new lists the 

 vowel variants have been excluded. They occur infrequently in 

 speech and phoneticians do not universely agree on their pronunciation. 

 For this reason they are not included. Also, the diphthongs I, ou, 

 oi, and ew, which were used in the old lists, were omitted from the 

 new lists. The last two of these diphthong sounds occur very infre- 

 quently in speech. Although the diphthongs, I and ou, do occur 

 quite frequently, it was felt that their essential properties were em- 

 braced by the properties of their constituent vowel sounds. By their 

 omission and also by the introduction of the compound st as a final 

 consonant, it is possible to construct any desired number of sylla- 

 bles of the con-vow-con type, from the speech sounds shown in the 

 table. 



