Miri, an Austronesian language spoken in northern Sarawak, Malaysia, has two sets of vowel changes that are conditioned by voiced obstruents. In the first set, a last-syllable low vowel is fronted and raised to [e], or less commonly [i], if a voiced obstruent appears earlier in the word, while a penultimate low vowel immediately following the trigger is skipped. In the second, a high vowel in the final syllable undergoes breaking (diphthongisation) or lowering, depending upon specific conditions, unless there is a voiced obstruent anywhere earlier in the word. For both triggers and suppressors, this effect is cancelled by an intervening blocking consonant, which includes any nasal or voiceless obstruent except glottal stop. The challenge is to understand why voiced obstruents have this double function, acting as a trigger with low vowels and a suppressor with high vowels, given the lack of an a priori transparent relationship between low vowel fronting and high vowel breaking/lowering.

We investigate the phonotactic behaviour of nasal consonants in a database of over 200 languages. Our findings challenge the common classification of nasals as intermediate between obstruents and liquids on the sonority hierarchy. Instead, we propose that there are two types of nasal consonants, one group with lower sonority than liquids and one with higher sonority. We propose that these two types of nasals differ in the presence or absence of a value for the feature [±continuant].

Substance-based phonological theories predict that a preference for phonetically natural rules (those which reflect constraints on speech production and perception) is encoded in synchronic grammars, and translates into learning biases. Some previous work has shown evidence for such biases, but methodological concerns with these studies mean that the question warrants further investigation. We revisit this issue by focusing on the learning of palatal vowel harmony (phonetically natural) compared to disharmony (phonetically unnatural). In addition, we investigate the role of memory consolidation during sleep on rule learning. We use an artificial language learning paradigm with two test phases separated by twelve hours. We observe a robust effect of phonetic naturalness: vowel harmony is learned better than vowel disharmony. For both rules, performance remains stable after twelve hours, regardless of the presence or absence of sleep.

An important question in phonology is to what degree the learner uses distributional information rather than substantive properties of speech sounds when learning phonological structure. This paper presents an algorithm that learns phonological classes from only distributional information: the contexts in which sounds occur. The input is a segmental corpus, and the output is a set of phonological classes. The algorithm is first tested on an artificial language, with both overlapping and nested classes reflected in the distribution, and retrieves the expected classes, performing well as distributional noise is added. It is then tested on four natural languages. It distinguishes between consonants and vowels in all cases, and finds more detailed, language-specific structure. These results improve on past approaches, and are encouraging, given the paucity of the input. More refined models may provide additional insight into which phonological classes are apparent from the distributions of sounds in natural languages.

To assess a phonological theory, we often compare its predictions to phonetic observations. This can be complicated, however, because it requires a theoretical model that maps from phonological representations to articulatory and acoustic observations. In this study we are concerned with the question of how phonetic observations are interpreted in relation to phonological theories. Specifically, we argue that deviations of observations from theoretical predictions do not necessitate the rejection of the theoretical assumptions. We critically discuss the problem of overinterpretation of phonetic measures by using syllable coordination for different speaker groups within Articulatory Phonology. It is shown that surface variation can be explained without necessitating substantial revision of the underlying phonological theory. These results are discussed with respect to two types of interpretational errors in the literature. The first involves the proliferation of phonological categories in order to accommodate variation, and the second the rejection of a phonological theory because the model which generates its predictions is overly simplified.