Three-year-old tone language learners are tolerant of tone mispronunciations spoken with familiar and novel tones

An important issue in language acquisition is understanding the function of suprasegmental information (e.g., tones) in spoken word recognition. Recent research found that three-year-old monolingual Mandarin learners recognized Mandarin words that were mispronounced using another Mandarin tone. This finding suggests that tone learners may have a tolerance of tone variation in spoken word recognition (i.e., their acceptance of tonally mispronounced words) by three years of age. However, it is also possible that the three-year-olds' tolerance of tone variation in spoken word recognition was merely driven by the children's familiarity with Mandarin tones, since the tone mispronunciations were produced using another Mandarin tone. This study examined whether three-year-old Mandarin learners can recognize words mispronounced using a novel tone that is unrelated to the Mandarin tone system, and whether their word recognition performance differs among words that are correctly pronounced, mispronounced with another Mandarin tone, and mispronounced with the novel tone. Two major findings emerged. First, spoken word recognition was faster on correctly pronounced words than on mispronounced words. Second, the children recognized the tested words regardless of pronunciation type, revealing a tolerance of tone variation in spoken word recognition. Thus, this study confirmed the recent discovery that tone acquisition exhibits a tolerance of tone variation around age three. In addition, this tolerance is not specific to tone mispronunciations produced using another Mandarin tone.