A cleft is a separation in the skin, tissue lining of the mouth, muscle, and/or bone that is normally fused together during fetal development; however, no structures are missing. This lack of fusion may result in a cleft lip and/or cleft palate. Hypernasal speech and articulation errors are often seen in the speech production of a patient with a cleft palate.
Hypernasal speech refers to a “nasal” sound that is heard in speech production. Nasal emission is audible air through the nose, which may also be present in someone with a cleft palate. In the English language, there are only 3 sounds that allow air to pass through the nose (m, n, ng). Some children may have weakness in closing off the nose from the mouth when speaking (sometimes even after surgical repair). Therefore, sounds that require a lot of air pressure may pass through the nose and result in nasal sound of speech. One may try to compensate for the inability with substituting or distorting sounds. Speech errors may either be due to normal development, structural deviations related to a cleft palate or learned behaviors.