Lenition in the production and perception of Chilean Spanish approximant consonants: Implications for lexical access models

Chilean Spanish approximant consonants [β̞ ð̞ ɣ̞] display high degrees of lenition, which often leads to elision in several phonetic contexts. The fact that these units can surface at any stage in a continuum from approximant to elided is an ideal testing ground for exploring how listeners attain lexical access while coping with varying degrees of acoustic and semantic information, and provides important evidence for evaluating the predictions that lexical access models make about processing highly degraded and variable signals. An initial production study was conducted to determine the scope of lenition for /b d g/ in Chilean Spanish. Ten native speakers were recorded while completing three elicitation tasks: word-lists, short texts and semi-guided conversations. Several duration, intensity and formant measurements were extracted, normalized and analysed. The results showed that lenition and elided variants are indeed a common feature of these consonants, and that the relevant variability is encoded in the interaction between duration, intensity and F1. Given this variation, the second study investigated how listeners resolve potential ambiguities in speech processing. Continua from approximant consonant to elision were prepared and presented to listeners in conditions which varied in the degree of acoustic and semantic cues available, in several perception tasks: phoneme monitoring, identification and discrimination. For phoneme monitoring and identification, the results for /b/ and /d/ showed category boundary shifts when semantic information became available, but no further semantic priming effects. No significant category boundary shifts were observed for /g/. The results from the discrimination tasks, on the other hand, showed that sensitivity to differences between consonant presence and elision rises as lenition increases. The results from the production and perception studies are discussed in the light of lexical access models, in particular with regard to the divide between abstractionist, episodic and hybrid models