Production Study of Spanish Spirantization in Naturalistic Speech

Résumé

Spanish spirantization is often cited as a case of phonetic reduction, in which oral closure movements are suggested to be produced in a failed/reduced form, and/or where speech muscles fail to achieve full activation. Other analyses treat spirantized variants as categorically distinct. The present study examines Spanish productions of the alveolar plosive /d/ in relation to its interdental variant in videos of natural speech produced by 12 Spanish speakers. Tokens of /d/ were contrasted to that of voiceless and nasal targets. Tokens were extracted, transcribed and coded for stress pattern and phonological environment by trained phoneticians. The area of visible tongue for /d/ in each video frame was measured and normalized. Differences in visible production indicate different active muscle groups for the dental /d/ vs. tongue protrusion in the interdental spirant. ANOVAs were performed on the area measurements, and chi-squared analyses were performed on the voiced, voiceless and nasal targets. Results indicate a bimodal distribution in tongue areas, indicating that the spirantized variants are produced with intent to achieve a separate target. This view is compatible with a modular approach to speech motor behavior.