Forty ESL students responded to extemporaneous stimuli produced by 4 ESL teachers of different language backgrounds. The listeners rated each stimulus for foreign accentedness and comprehensibility (estimation of difficulty in understanding an utterance) on 9-point scales. They also answered comprehension questions to measure speakers’ interpretability and transcribed each stimulus in standard orthography to assess speakers’ intelligibility. The results showed that accentedness, perceived comprehensibility, intelligibility, and interpretability of NNESTs were all independent dimensions, except for an influence of accentedness on perceived comprehensibility (r = 0.503, p < 0.001, 2-tailed). Foreign-accented speech was only believed to be difficult to understand. Thus, the hypothesis that ESL students’ negative attitudes are the result of reduced intelligibility and interpretability of NNESTs’ foreign-accented speech was not supported in this study. Interestingly, students’ high word-recognition rate did not entail better understanding of the utterance.