Results from a pilot study show that when vowel deletion is triggered in Yoruba (VV → V), the resulting vowel is slightly but significantly longer than a normal short vowel in the language, by about 10ms. If this effect is robust, it has implications for both phonology and phonetics: how is this process modeled? Over what representations does it operate? Is this phonological lengthening or phonetic lengthening? Future studies will investigate a broader range of vowels, in more contexts, across more speakers.