The authors present a model of the phonotactic and orthographic constraints of Australian and Standard Southern British English monosyllables. This model is used as the basis for a web-based psycholinguistic resource, the ARC Nonword Database, which contains 358,534 monosyllabic nonwords--48,534 pseudohomophones and 310,000 non-pseudohomophonic nonwords. Items can be selected from the ARC Nonword Database on the basis of a wide variety of properties known or suspected to be of theoretical importance for the investigation of reading.

The aim of the study was to establish whether /u/-fronting, a sound change in progress in standard southern British, could be linked synchronically to the fronting effects of a preceding anterior consonant both in speech production and speech perception. For the production study, which consisted of acoustic analyses of isolated monosyllables produced by two different age groups, it was shown for younger speakers that /u/ was phonetically fronted and that the coarticulatory influence of consonants on /u/ was less than in older speakers. For the perception study, responses were elicited from the same subjects to two minimal word-pair continua that differed in the direction of the consonants' coarticulatory fronting effects on /u/. Consistent with their speech production, young listeners' /u/ category boundary was shifted toward /i/ and they compensated perceptually less for the fronting effects of the consonants on /u/ than older listeners. The findings support Ohala's model in which certain sound changes can be linked to the listener's failure to compensate for coarticulation. The results are also shown to be consistent with episodic models of speech perception in which phonological frequency effects bring about a realignment of the variants of a phonological category in speech production and perception.

The extent to which it is necessary to model the dynamic behavior of vowel formants to enable vowel separation has been the subject of debate in recent years. To investigate this issue, a study has been made on the vowels of 132 Australian English speakers (male and female). The degree of vowel separation from the formant values at the target was contrasted to that from modeling the formant contour with discrete cosine transform coefficients. The findings are that, although it is necessary to model the formant contour to separate out the diphthongs, the formant values at the target, plus vowel duration are sufficient to separate out the monophthongs. However, further analysis revealed that there are formant contour differences which benefit the within-class separation of the tense/lax monophthong pairs.

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In this paper we analyse the extent to which an adult's vowel space is affected by vowel changes to the community using a database of nine Christmas broadcasts made by Queen Elizabeth II spanning three time periods (the 1950's; the late 1960's/early 70's; the 1980's). An analysis of the monophthongal formant space showed that the first formant frequency was generally higher for open vowels, and lower for mid-high vowels in the 1960's and 1980's data than in the 1950's data, which we interpret as an expansion of phonetic height from earlier to later years. The second formant frequency showed a more modest compression in later, compared with earlier years: in general, front vowels had a decreased F2 in later years, while F2 of the back vowels was unchanged except for [u] which had a higher F2 in the 1960's and 1980's data. We also show that the majority of these Fl and F2 changes were in the direction of the vowel positions of 1980's Standard Southern British speakers reported in Deterding (1997). Our general conclusion is that there is evidence of accent change within the same individual over time and that the Queen's vowels in the Christmas broadcasts have shifted in the direction of a more mainstream form of Received Pronunciation.