Phonetic reduction versus phonological deletion of French schwa: Some methodological issues

A categorical phonological process of deletion is traditionally assumed to account for the alternation of schwa with zero in French. This process is assumed to result in two discrete outputs: forms with schwa (i.e., schwa variants) and forms without schwa (i.e., non-schwa variants). However, the two studies we present here suggest a more complex picture. In the first study, we investigate the phonetic variability of schwa in a large number of occurrences of schwa variants and find that schwa, like other segments in French, undergoes phonetic reduction. As a consequence, some tokens without schwa in connected speech may be the result of a process of gradual phonetic reduction rather than the result of a categorical process of alternation. In the second study, we examine the perception of schwa word tokens extracted from connected speech. We show that deciding whether a token was produced with or without the schwa is not always possible. Furthermore, listeners rely on other types of cues than acoustic ones in order to make their judgements (i.e., speech rate, word length and segmental context). These findings have important theoretical and methodological implications that must be taken into account in the empirical study of French schwa alternation.

Research highlights
► French schwa, when realized, undergoes phonetic reduction like other segments.
► The distinction between schwa and non-schwa variants can be perceptually ambiguous.
► The perception of schwa does not depend exclusively on acoustic cues.
► Results raise methodological issues on the distinction between reduction and deletion.