The
Language ENvironment Analysis system (LENA) records children’s language
environment and provides an automatic estimate of adult–child conversational
turn count (CTC). The present study compares LENA’s CTC estimate to manually
coded CTC on a sample of 70 English-speaking infants recorded longitudinally
at 6, 10, 14, 18, and 24 months of age. At each age, LENA’s CTC was
significantly higher than manually coded CTC (all ps < .001, Cohen’s ds:
0.9–2.05), with the largest discrepancies between the two methods observed at
younger ages. The Limits of Agreement Analyses confirm wide disagreements
between the two methods, highlighting potential problems with automatic
measurement of parent–infant verbal interaction. These findings suggest that
future studies should validate LENA’s CTC estimates with manual coding.
