Obligatory Nasal Turbulence as a Trigger for the Development of Posterior Nasal Fricatives in a Child With Repaired Cleft Palate.

Posterior nasal fricatives (PNFs) are unusual articulations that occur in some children with and without cleft palate. The etiology of PNFs is unclear. A young girl with repaired cleft palate is described who exhibited inconsistent obligatory nasal turbulence during production of stops at 2 years of age. At 3 years of age, she exhibited various phonological processes and used PNFs to replace sibilants and affricates. Pressure-flow testing showed a relatively small velopharyngeal area during production of stops. These observations are consistent with obligatory nasal turbulence triggering the development of PNFs as an unusual phonological process, perhaps facilitated by reduced hearing.