Pronunciation learners can benefit from peer feedback in a Computermediated Communication (CMC) environment that allows them to notice segmentals and suprasegmentals. This paper explores the intelligibility judgments of same-L1 peers using P-Check (Version2, https://ver2.jp), a Learning Management System (LMS) plug-in that aggregates peer feedback on local intelligibility (Munro & Derwing, 2015). P-Check randomly delivers written prompts for learners to record. Recordings are randomly delivered to peers who choose from a drop-down menu which utterance was perceived. Aggregated judgments from peers and from the instructor are displayed to learners as feedback on intelligibility. This study used eight segmental contrasts: /b-v/, /s-[theta]/, /l-[alveolar approximant]/, /l-[alveolar approximant]/-clusters, /[ash]-[lambda]/, /[open back unrounded vowel]-[lambda]/, /[open back unrounded vowel]-o[near-close near-back vowel]/, and /i-[near-close near-front unrounded vowel]/. Participants (N=38) made 3,451 intelligibility judgments on 1,203 recordings. The effects of rater listening discrimination proficiency and of utterance intelligibility were examined in six contrasts using Generalized Estimating Equations (GEE). Results showed that intelligibility was generally a significant predictor of judgment accuracy, but rater listening discrimination proficiency was not. [For the complete proceedings, see ED600837.]