Purpose This study examined the perceptual accuracy and subjective difficulty of articulatory error types in the Korean alveolar fricatives /s/ and /s*/ among speech-language pathology trainees and explored the relationship between these two measures. Methods Participants were 32 undergraduate speech-language pathology students (29 females, 3 males; mean age = 26.9 years, SD = 8.6) from two universities in Busan and Jeonnam, Korea. The stimuli consisted of 24 familiar words containing /s/ or /s*/ in word-initial or word-medial position, each combined with one of six monophthongs (excluding /i/). Each word was recorded under five conditions correct production, — plosivization, interdentalization, palatalization, and lateralization—yielding 120 stimuli. Perceptual accuracy was analyzed using generalized linear mixed models (GLMM), and subjective difficulty was analyzed using linear mixed models (LMM). Results The main effect of articulatory error type was significant for both perceptual accuracy (F = 51.41, p < .001) and subjective difficulty (F = 188.30, p < .001). Perceptual accuracy was highest for correct production (.94) and plosivization (.92) and lowest for interdentalization (.54). Subjective difficulty ratings were highest for lateralization (3.16) and lowest for correct production (1.36). A discrepancy between perceptual accuracy and subjective difficulty was observed, suggesting that perceptual performance and metacognitive judgments may reflect different underlying processes. Conclusions Articulatory error type is a key factor in speech perception. These findings highlight the need for perceptual training in clinical education that addresses both identification accuracy and learners’ perceptual awareness.