The objective of this study was to investigate changes in the natural language environments of families with typically-developing infants receiving language feedback in South Korea. Volunteer parents of 99 children aged 4-16 months were randomly divided into experimental and control groups. During 6 months' intervention, the experimental group recorded weekly day-long automatically-analyzed LENA measures of language environment and viewed feedback, while the control group recorded only baseline, mid-period and post-test without feedback. LENA Adult Word Counts (AWC) and Conversational Turn (CT) counts correlated reasonably well with human transcripts. At baseline groups were not significantly different. At post-test there was no significant overall difference between experimental and control groups, but AWC and CT differences were significant for families below the 50th percentile at baseline. Korean parents whose linguistic environment was below average adapted their communicative interaction in response to linguistic feedback. The intervention has promise for use with at-risk families in many countries.