Spanish is often described as a language that lacks word-internal geminate consonants. This study explores an ongoing sound change in Andalusian Spanish whereby /ɾn/ and /ɾl/ sequences undergo gemination (i.e., [n:] and [l:], respectively), due to phonetic assimilation of clusters involving coronal sonorants. This change now creates a lexical contrast between non-geminate [n]/[l] and geminate [n:]/[l:] in pairs orthographically represented as pela ‘s/he peals’ - perla ‘pearl’, cala ‘cove’ - Carla ‘Carla’, and tono ‘tone’ - torno ‘window’, among many others. In this project we consider two acoustic parameters of this contrast: consonant duration and formant frequency (F1, F2 & F3).

In Experiment 1, 17 Andalusian speakers and 10 Castilian speakers participated in a carrier phrase reading task to test the acoustic differences between orthographic rl, rn and l, n sequences. The Andalusian speakers produced rl, rn sequences as geminate [l:] and [n:], and their duration was nearly twice as long as non-geminate l, n (ratio = 1.90). We also extracted duration values and formant frequencies of the vowels preceding and following these consonants, but significant differences did not emerge in the singleton-geminate comparisons. On the other hand, the Castilian speakers showed shorter [n] and [l] durations in rl, rn sequences compared to l, n, indicating non-geminate production in both conditions. In Experiment 2, 10 Andalusian speakers read sentences designed to test durational differences in lexical geminates (of the types identified in Experiment 1) and syntactic geminates. The results show non-significant differences between conditions, adding further support to the claim that the only universal acoustic feature that we can reliably identify for geminates may be constriction duration (Kawahara, 2015). To conclude, we provide implications for the structural status of Andalusian geminates (including certain prosodic restrictions) and present ideas for an ongoing perception study.