RESUMO
Objective: The aim of this study is to analyze the development of speech ability in Mandarin-speaking infants and children with normal hearing using MUSS and to provide a normal value control for the evaluation of speech ability in children with hearing loss. Methods: From September 2012 to January 2023, a total of 256 infants and children aged 1-60 months in Mandarin language environment participated in this study. 200 infants and children aged from 1 to 60 months were finally included, whose hearing was considered normal according to the history collection, high-risk registers for hearing loss and hearing screening. All infants and children were divided into 10 groups with 20 infants or children in each group. They were: 1 month, 2-3 months, 4-6 months, 7-9 months, 10-12 months, 13-18 months, 19-24 months, 25-36 months, 37-48 months, and 49-60 months. Using SPSS 19.0 software for data analysis, we calculated regression equations based on fitting curves. Results: The language ability of infants and children with normal hearing increased with age and reached ceiling at 56.5months.The regression equation was: score=-0.009 3×(age) 2+2.179×(age)+6.718 6, r2=0.85; age=0.003 9×(score) 2+0.148 4×(score)+2.708, r2=0.85. Conclusions: The speech ability of infants and children with normal hearing shows an increasing trend with age. Scores of different speech skills can be predicted according to their age. Age can also be predicted according to their scores of different speech skills.