Obstruent voiced obstruents are common. This contrasts with sonorants, which are prototypically voiced and only rarely voiceless. Obstruent An obstruent is a speech sound such as , , or that is formed by "obstructing" airflow. Obstruents contrast with sonorants, which have no such obstruction and so resonate. All obstruents are consonants, but sonorants include both vowels and consonants. Obstruents are subdivided into plosives (oral stops), such as , with complete occlusion of the vocal tract, often followed by a release burst; fricatives, such as , with limited closure, not stopping airflow but making it turbulent; and affricates, which begin with complete
Speech sound disorder often need the services of a Speech-Language Pathologist to learn correct speech sounds. Some speech sound errors can result from other syndromes or disorders such as: In a typical 2-year-old child, about 50% of speech may be intelligible. A 4-year-old child's speech should be intelligible overall, and a 7-year-old should be able to clearly produce most words consistent with community norms for their age. Misarticulation of certain difficult sounds ("l", "r", "s", "z", "th", "ch", "dzh", and "zh") may be normal up to 8 years. Children with speech sound disorder have pronunciation difficulties inappropriate for their age, and the difficulties