The Neighborhood Activation Model (NAM) has emphasized an importance of lexical factors (target word neighborhood, neighborhood density, and average word frequency of neighborhood) for recognition of spoken words as well as for development of speech audiometry materials. The purpose of this study was 1) to determine lexical equivalence across Korean standard monosyllabic word lists for adults or school-aged children (Kim et al., 2008a, 2008b) in experiment I, and 2) to investigate the effects of three lexical factors on spoken word recognition in experiment II. To examine lexical effects on word recognition in the experiment II, Korean standard monosyllabic word lists for adults or school-aged children were analyzed by three lexical aspects (target word neighborhood, neighborhood density, and average word frequency of neighborhood) and then resorted into lexically easy word list (E-list) or lexically hard word list (H-list). Adults (N = 14) and children (N = 16) with normal hearing participated in the experiment II of this study. Results of experiment I showed that the four monosyllabic lists for both adults and school-aged children did not differ by each of the three lexical factors, confirming lexical equivalence across lists. Results of experiment II showed that, regardless of listener group, E-list words were recognized with significantly greater accuracy compared to H-list words. Especially the performance difference between E-list and H-list was greater in children than in adults, indicating a stronger impact of lexical aspects on children. Results of error analysis for word recognition showed that wrong answers of both listener groups occurred more frequently from neighbor words than from non-neighbor words.