E-Mail Languages differ in the sounds they use. The Japanese language, for example, does not distinguish between "r" and "l" sounds as in "rock" versus "lock." Remarkably, infants become attuned to the sounds of their native language before they learn to speak. One-year-old babies, for example, less readily distinguish between "rock" and "lock" when living in an environment where Japanese, rather than English, is spoken. Influential scientific accounts of this early phonetic learning phenomenon initially proposed that infants group sounds into native vowel- and consonant-like phonetic categories through a statistical clustering mechanism known as "distributional learning." The idea that infants learn consonant- and vowel-like phonetic categories has been challenged, however, by a new study published this week in the