Canonical babbling, or the production of adult-like consonant-vowel syllables in infancy, represents a critical milestone in prelinguistic vocal development and predicts later speech and language outcomes. This systematic review and meta-analysis synthesized findings from 42 studies and 1277 infants aged 5-24 months across 16 language environments to examine how methodological and contextual factors influence the most common measure of canonical babbling: the canonical babbling ratio (CBR). Resu