On the small flat vowel systems of Australian languages

Abstract

The vowel systems of Australian languages could best be characterized as “small and flat.” Small, because about 50% of Australian languages have a three-vowel system with another 20% or so distinguishing four or five vowel qualities. Flat, because, while there is the usual degree of separation between front and back vowels along the horizontal (F2) axis of the vowel space (700–2400 Hz), variation along the vertical (F1) axis is typically restricted to a range of 350-900 Hz, leaving the ‘close’ vowel area noticeably under-exploited. Thus, rather than the [i, a, u] values as traditionally transcribed, 3-vowel languages have the phonetic (Cardinal Vowel) qualities of [e, ɐ, o] and 5-vowel languages have [e, ɛ, ɐ, ɔ, o]. I suggest that, as with the atypical consonant inventories, the lack of close vowels in these languages may be explained in terms of the historical influence of the hearing status of their speakers. Reduction in vowel space in individual speakers is one consequence of hearing impairment caused by otitis media, which can reduce hearing levels under 500 Hz by up to 40 dB. The Australian Aboriginal population has the highest prevalence of otitis media in the world by far (50 to 90%).