Adequately accounting for patterns of dissimilation has challenged more than one linguistic theory. This paper brings together evidence for certain recurrent patterns of dissimilation in Austronesian and Australian languages. It does not claim to have found a definitive solution to why these patterns occur, but it does provide indications that avoidance of multiple markedness may be causally implicated. Although the emphasis is different, the proposal offered here thus has fundamental similarities with Alderete (1997) in arguing that where it applies to dissimilation the Obligatory Contour Principle is inseparably connected with marked elements. Its primary contributions are to provide further empirical support for this claim that may not be readily accessible to non-specialists, to generalise the claim to a larger class of data, to suggest that the explanation for such patterns may be cognitive rather than phonetic and particularly to draw attention to conditions under which markedness-triggered dissimilation is suppressed.

Under the weak layering approach to prosodic structure (Itô & Mester 1992), the requirement that output forms be exhaustively parsed into binary feet, even when the input contains an odd-number of syllables, results in the odd-parity input problem, which consists of two sub-problems. The odd heavy problem is a pathological type of quantity-sensitivity where a single odd-numbered heavy syllable in an odd-parity output is parsed as a monosyllabic foot. The even output problem is the systematic conversion of odd-parity inputs to even-parity outputs. The article examines the typology of binary stress patterns predicted by two approaches, symmetrical alignment (McCarthy & Prince 1993) and iterative foot optimisation (Pruitt 2008, 2010), to demonstrate that the odd-parity input problem is pervasive in weak layering accounts. It then demonstrates that the odd-parity input problem can be avoided altogether under the alternative structural assumptions of weak bracketing (Hyde 2002).

The set of neutral vowels in the vowel-harmony pattern found in Modern Korean sound-symbolic words is traditionally considered to consist of two members: [i] and [ɨ]. Some authors have tentatively put forward the hypothesis that [u] and [y] are also neutral. A corpus study on the phonotactics of Korean sound-symbolic vowel harmony provides quantitative support both for the traditional understanding of [i] and [ɨ] as neutral vowels and for the tentative hypothesis that [u] and [y] are also neutral. Additionally, the corpus study reveals that vowels are neutral to different degrees. The vowel [a] is shown to be partially neutral, but unlike the other neutral vowels which are transparent, [a] is partially opaque. The distribution of diphthongs is also studied.

During the fixed initial-stress period of Latin (sixth to fifth centuries BC), internal open syllable vowels were totally neutralised, usually raising to /i/ (*per.fa.ki.oː>perficiō ‘I complete’), whereas in closed syllables /a/ was raised to /e/, but the other vowels remained distinct (*per.fak.tos>perfectus ‘completed’). Miller (1972) explains closed syllable resistance by positing internal secondary stress on closed syllables. However, evidence from vowel reduction and syncope suggest that internal syllables never bore stress in early archaic times. A typologically unusual alternative is proposed: contrary to the pattern normally found (Maddieson 1985), vowels had longer duration in closed syllables than in open syllables, as in Turkish and Finnish, thus permitting speakers to attain the targets for non-high vowels in closed syllables. This durational pattern is manifested not only in vowel reduction, but also in the quantitative changes seen in ‘classical’ and ‘inverse’ compensatory lengthenings, the development CVːCV > CVC and ‘superheavy’ degemination (VːCCV > VːCV).

Norwegian retroflexion exhibits some phonetic properties that do not seem to ‘make sense’. In Standard East Norwegian, an alveolar /ɾ/ causes a following alveolar coronal to become postalveolar, and in the Frogner and Arendal dialects of Norwegian, the same postalveolarisation process is triggered by a uvular /ʁ/. Comparative analyses of Norwegian dialects reveal that these properties are the results of historical changes and phonological diffusion across dialects. Theories attempting to analyse Norwegian retroflexion as phonetically ‘natural’ can neither fully account for these properties of Norwegian retroflexion nor capture the typological generalisations found across Norwegian dialects.