Morphology beyond the morpheme: distributed processing effects in the acoustic realization of German word-final clusters

This study investigates how morphological structure shapes phonetic realization in German word-final /Cst/ clusters, with a focus on form-meaning mapping strategies in elicited speech. Phonologically identical clusters are compared across simplex words and inflected verb forms, where /st/ encodes a grammatical morpheme. We analyse duration, intensity, and spectral center of gravity (COG) for clusters, individual segments, and adjacent vowels, modeling their variation with linear mixed-effects models. Rather than yielding uniform phonetic shifts, morphology-related effects emerge as context-sensitive patterns modulated by lexical and phonetic factors. Temporal effects primarily take the form of durational reduction in of morphemic segments, but they extend to surrounding phonetic material, where they manifest as lengthening. In addition, increased intensity and spectral sharpening are associated with morphemic shortening, calling for a more comprehensive interpretation of phonetic reduction and its relationship with morphological function. Overall, the results are in line with approaches to speech production that move beyond a strictly modular view and posit dynamic interactions between morphological and phonetic information within the cognitive system.