This book provides an integrated account of the phonetic causes of the diachronic processes of palatalization and assibilation of velar and labial stops and labiodental fricatives, as well as the palatalization and affrication of dentoalveolar stops. While previous studies have been concerned with the typology of sound inventories and of the processes of palatalization and assibilation, this volume not only deals with the typological patterns but also outlines the articulatory and acoustic causes of these sound changes.

In his articulation-based account, Daniel Recasens argues that the affricate and fricative outcomes of these changes developed via an intermediate stage, namely an (alveolo)palatal stop with varying degrees of closure fronting. Particular emphasis is placed on the one-to-many relationship between the input and output consonant realizations, on the acoustic cues that contribute to the implementation of these sound changes, and on the contextual, positional, and prosodic conditions that most favour their development. The analysis is based on extensive data from a wide range of language families, including Romance, Bantu, Slavic, and Germanic, and draws on a variety of sources, such as linguistic atlases, articulatory and acoustic studies, and phoneme identification tests.

The book investigates historical patterns of vowel diphthongization, assimilation and dissimilation induced by consonants – mostly (alveolo)palatals – in Romance. Compiling data from dialectal descriptions, old documentary sources and experimental phonetic studies, it explains why certain vowels undergo raising assimilation before (alveolo)palatal consonants more than others. It also suggests that in French, Francoprovençal, Occitan, Rhaetoromance and dialects from northern Italy, mid low vowel diphthongization before (alveolo)palatal consonants started out with the formation of non-canonical falling diphthongs through off-glide insertion, from which rising diphthongs could emerge at a later date (e.g., Upper Engadinian OCTO ‘eight’ > [ɔc] > [ɔ(ə̯)c] > [wac]). Both diphthongal types, rather than canonical falling diphthongs with a palatal off-glide, could also give rise to high vowels (dialectal French [li] < LECTU, [fuj] < FOLIA). This same Gallo-Romance diphthongization process operated in Catalan ([ʎit], [ˈfuʎə]). In Spanish, on the other hand, mid low vowels followed by highly constrained (alveolo)palatals became too close to undergo the diphthongization process ([ˈletʃo], [ˈoxa]).