Hiatus occurs when the juxtaposition of syllables results in two separate vowels occurring alongside one another. Such vowel adjacency, both within words and across word boundaries, is phonologically undesirable in many languages but can be resolved using a range of strategies including consonant insertion. This paper examines linguistic and extralinguistic factors that best predict the likelihood of inserted linking ‘r’ across word boundaries in Australian English. Corpus data containing a set of 32 phrases produced in a sentence-reading task by 103 speakers were auditorily and acoustically analysed. Results reveal that linguistic variables of accentual context and local speaking rate take precedence over speaker-specific variables of age, gender and sociolect in the management of hiatus. We interpret this to be a reflection of the phonetic manifestation of boundary phenomena. The frequency of the phrase containing the linking ‘r’, the frequency of an individual's use of linking ‘r’, and the accentual status of the flanking vowels all affect the /ɹ/ strength (determined by F3), suggesting that a hybrid approach is warranted in modelling liaison. Age effects are present for certain prosodic contexts indicating change in progress for Australian English.
