Segments Inventories and Syllable Inventories

Another hypothesis is that the size of the segment inventory is related to the phonotactics of the language in such a way as to limit the total number of possible syllables that can be constructed from the segments and suprasegmental properties that it has. Languages might then have approximately equal numbers of syllables even though they differ substantially in the number of segments. Rough maintenance of syllable inventory size is evisaged as the functional of cyclic historical processes by, for example, Matisoff (1973). He outlines an imaginary language in which, at some arbitrary stating point, "the number of possible syllables is very large since there is a rich system of syllable-initial and -final consonants". At a later stage of the language these initial and final consonantal systems are found to have simplified but "the number of vowels has increased and lexically contrastive tones have arisen" maintaining contrasting syllabic possibilities. If tone or vowel contrasts are lost, consonat clustering will increase at the syllable margins again.

A brief investigation of the relationship between segmental inventory size and syllable inventory size was carried out by calculating the number of possible syllables in 9 languages. The languages are Tsou (418), Quechua (819), Thai (400), Rotokas (625), Gã (117), Hawaiian (424), Vietnamese (303), Cantonese, Higi, and Yoruba (the last three are not in UPSID but detailed data on the phonotactics are available in convenient form for these languages). The 9 languages range from those with small segment inventories (Rotokas, Hawaiian) to those with relatively large inventories (Vietnamese, Higi, Quechua) and from those with relatively simple suprasegmental properties (Tsou, Hawaiian, Quechua) to those with complex suprasegmental phenomena (Yoruba, Thai, Cantonese, Vietnamese). In calculating the number of possible syllables, general co-occirrence restrictions were taken into account, but the failure of a particular combination of elements to be attested if parallel combinations were permited is taken only as evidence of an accidental gap, and such a combination is counted as a possible syllable. The calculations reveal very different numbers of possible syllables in these languages. The totals are given in Table 1.5.

Table 1.5 Syllable inventory size of 9 selected languages
Language	Total possible syllables
Hawaiian	162
Rotokas	350
Yoruba	582
Tsou	968
Gã	2,331
Cantonese	3,456
Quechua	4,068
Vietnamese	14,430
Thai	23,638

Even with the uncertainties involved in this kind of counting, the numbers differ markedly enough for the conclusion to be drawn that language are not strikingly similar in terms of the size of their syllable inventories.

In following up this study, several tests were done to see which of a number of possible predictors correlated best with syllable inventory size. The predictors used were the number of segments, the number of vowels, the number of consonants, the number of permitted syllable structures (CV, CVC, CCVC, etc.), the number of suprasegmental contrasts (e.g. number of stress levels time number of tone), and a number representing a maximal count of segmental differences in which the number of vowels was multiplied by the number of suprasegmentals. Of these, the best predictor is the number of permitted syllable types (r = .69), an indication that the phonotactic possibilities of the language are the most important factor contributing to the number of syllables. The next best predictor is the number of suprasegmentas (r = .59), with the correlation with the various segmental counts all being somewhat lower. Although all the predictors tested show a positive simple correlation with the number of syllables, in a multiple regression analysis only the number of vowels contributes a worthwhile improvement to the analysis (r^2 change = .19) beyond the number of syllable types. Thus we can say that syllable inventory size does not depend heavily on segment inventory size. Nonetheless, because the predictors do have positive correlations with syllable inventory size, the picture is once
again of a tendency for complexity of different types to go together.

(Patterns of Sounds, Ian Maddieson)