A cleft palate is a birth defect in which the soft tissues of the palate did not grow together during pregnancy. There is often an opening left between the roof of the mouth and the nasal cavity, though some children may experience clefting at both the front and back of the palate while others may only have partial clefting of these tissues.
There are different types and degrees of severity of clefts.
In the Unilateral cleft palate, there is a split on one side of the roof of the mouth whereas in the Bilateral cleft palate there is clefting on both sides of the palate.
That can cause significant obstacles for children's speech. It involves an opening or split in the oral structures that can be surgically repaired at a very early age.
Although the surgeon may be successful in closing the cleft, it is often possible that difficulties with speech may develop. Cleft Palate is highly associated with speech problems. Research has proved that more than half of the children who are born with cleft palate are in need of speech therapy at some point during childhood. This will lead them to normal speech development by the age of 5.
Before the palate is repaired, there is no separation between the nasal cavity and the mouth. This means that the child cannot build up air pressure in the mouth because air escapes out of the nose, and there is less tissue on the roof of the mouth for the tongue to touch. Both of these problems can make it difficult for the child to learn how to make some sounds.
The child who is born with a cleft palate is prone to show a delay in both the onset of speech and the development of speech sounds during the first 9-24 months of age. Thus, it is important for the child not be excluded from any conversations.
Problems with language delay may occur because of the child's inability to produce certain sounds. Compensatory speech patterns usually develop which makes it very difficult for adults to understand. As a result, this affects the child's interaction with adults and peers. Articulation can also be affected by the cleft palate if the soft palate cannot make contact with the pharyngeal walls. Airflow will leak through the nose during speech. This is called hypernasal speech. Such speech can affect consonant sounds "p", "b", "t", "d", "s", "sh", "ch", and "f" if the seal cannot be maintained. As the air escapes, the sounds will become distorted. The voice quality can indicate signs of hypernasality and other problems with resonance. In addition to problems with language and articulation, repeated ear infections and dental issues can further complicate speech and language of a cleft palate child. Often, the early and late eruption of teeth in connection with the collapse of the upper jaw further complicate the cleft lip/palate child's ability to develop speech and language skills in the traditional method.
Other speech problems involve the inability of the child to use hard palate as main site of articulation, preferring sounds that do not require contact with palate.
The cleft palate child is unable to produce labial and alveolar consonants due to the nature of the defect. The Palatals and alveolars are not heard until after palatal repair. There is abundance of glottal stops and inadequate velopharyngeal closure. As it was mentioned above all high nasal quality to speech is also indicated.
The cleft palate child’s speech is characterized by lack of control over oral airflow and a delay in onset of canonical glottal. Therefore, the articulation is weak and there is a less variety among consonants and multisyllabic utterances. The phonetic repertoire is also limited.
Once the problem is restored, the speech is produced correctly. That is the soft palate lifts and moves toward the back of the throat, separating the nasal cavity from the mouth. In this way, the air and sound can be directed out of the mouth. The inability to close off the nasal cavity from the mouth is called velopharyngeal inadequacy. Children who have velopharyngeal inadequacy may sound like they are “talking through their noses.”
All children who are born with cleft palate have velopharyngeal dysfunction resulting in hypernasality until the cleft is repaired. After repair, some children still have velopharyngeal dysfunction. This explained by the fact that when the soft palate cannot close off the nose from the mouth, air and sound can escape through the nose during speech, possibly resulting in hypernasality and nasal emission of air. Approximately 25% of children with repaired cleft palates still show signs of velopharyngeal inadequacy.
The child may also produce “grunt” or “growl” sounds. These sounds are produced due to the child’s effort to compensate for velopharyngeal inadequacy. This behaviour usually begins before the palate is repaired, but it may continue even after the palate is closed. Children find it extremely hard to overcome this habit.
Children with velopharyngeal inadequacy may also have a voice disorder. In this case, your child’s voice may sound hoarse or “breathy” and may fatigue easily. This is usually caused by the strain that the child puts on the vocal cords while trying to build the pressure necessary for normal speech.
The goal of therapy speech therapy in such cases is to help a child learn to use his/her tongue and lips correctly. Therapy may also be an effective treatment option for mild hypernasality but it usually does not correct more serious velopharyngeal dysfunction.Theodora Papadopoulou, PhD