PURPOSE: To compare the productions of [s] and [∫] of adults and children with typical phonological development considering the following acoustic parameters: duration of fricative noise, frequency band of higher concentration of noise, cutoff frequency of friction noise, and values of formant transition of the following vowel. METHODS: Participants were 26 subjects, divided into two groups: Adults group (AG) - composed of 17 young adults (mean age: 23.61±3.44 years) without phonological disorders; and Typically developing children group (TDCG) - composed of nine children (mean age: 7.12±0.74 years) within typical phonological development. Subjects underwent speech-language pathology and audiology screening, and then data collection for acoustic analysis. For acoustic analysis, pseudowords in carrier phrases were used. We analyzed 624 productions from the subjects, and the results were statistically analyzed. RESULTS: The parameters frequency band of higher concentration of noise and formant transition of the following vowel presented differences between groups. In the comparison between word positions, the parameters duration and cutoff frequency of fricative noise, and formant transition of the following vowel presented differences. The parameters frequency band of higher concentration of noise, cutoff frequency of friction noise, and formant transition of the following vowel showed statistical differences in the comparison between the points of articulation of [s] and [∫]. CONCLUSION: For most of the studied acoustic parameters, children's and adults' productions were similar. However, for some parameters, differences were observed between groups, word positions, and pois of articulation of the phonemes [s] and [∫].