BACKGROUND: characteristics of voiceless fricative sounds PURPOSE: to review the literature related to acoustic, phonetics and phonological characteristics of voiceless fricative sounds that are part of the phonological system of the Portuguese Language. Furthermore, it describes the use of these sounds in voice therapy. CONCLUSIONS: fricatives are acute phonemes comprised between 2500 and 8000 Hz; they are fully acquired up to the age of 3:7 years; the /s/, which is the most affected in cases of short lingual frenum; omission of the /s/ is one of the most frequent occurrences during literacy education; and in the phonological deviation and labial-palatine fissure the entire class of fricatives is frequently affected. In voice assessment, fricative sounds are mentioned as TMF measurements and s/z relationship, and their use as support sounds in speech therapy.
Voice; Phonetics; Voice Training; Speech Therapy