In Brief:
This study investigated if intelligibility of the patient’s own speech, measured via a vowel identification test (VOW), can predict cochlear implant success in terms of speech perception, for prelingually deaf adults. Data from 77 patients showed that postimplant speech perception correlated positively with VOW (r = 0.79, p < 0.00001), and that the probability that a patient with VOW ≥ 60% achieves “above-chance” speech perception after implantation is about 0.9, against 0.25 for a patient with VOW < 60%. The binary classification based on VOW and associated probabilities of cochlear implant success may support patient counselling and implant candidacy decisions.