Phonetics and phonology of schwa insertion in Central Yiddish

Central Yiddish (CY) has inserted schwas that occur between long vowels or diphthongs and certain coda consonants. In the most restrictive varieties, schwas are inserted only between long high vowels or diphthongs and uvular or rhotic codas (as in /biːχ/ → [biːəχ] ‘book’), and between long high vowels or diphthongs and coronal codas, as long as the vowel is [+back] (as in /ʃuːd/ → [ʃuːəd] ‘shame’). These patterns of insertion are both typologically unusual and synchronically hard to explain. In this paper, I argue that they can be traced back to the phonetic transitions between specific vowels and coda consonants: vowel-coda sequences that produce formant transitions through the mid-central acoustic vowel space are those that are most likely to exhibit schwa insertion. An analysis of 19th-century CY verse demonstrates that these inserted schwas were intended to count for purposes of poetic rhyme, suggesting that they are phonological schwas rather than exclusively phonetic transitions. This study thus adds to the phonological description and analysis of Central Yiddish, and provides novel predictions regarding the spreading of vowel epenthesis across different phonological environments.