The effects of Cleft Lip/Palate on Communication

A history of Cleft lip or palate can affect the child's ability to develop verbal communication skills.  The following aspects of vernal communication may be defective.

Articulation(Speech)-the physical production of sounds to form spoken words

Language-the message conveyed back and forth in talking.  This includes the ability to understand the speech of others (receptive language) and the ability to express thoughts through words and sentences (expressive language).

Voice-the sound that results from the vibration of the vocal cords (phonation).

Resonance-the vibration of voiced sound in the oral cavity (mouth, and nasal cavity (nose).

Dental Abnormalities

If the cleft extended into the gum ridge, dental development may be affected, causing the following:
-Missing teeth in the area of the cleft
-Extra teeth
-Malocclusion(poor closure of the top and bottom jaws)

Dental abnormalities may cause speech errors as follows:
-A lisp type of distortion on sibilant sounds (/s/, /z/, /sh/, /ch/, /j/)
-Difficulty producing teeth to lip sounds (/p/, /b/, /m/)
-Difficulty producing teeth to lip sounds (/f/, /v/)
-Difficulty producing tongue-tip sounds (/t/, /d/, /n/, /l/)

These distortions can usually be corrected with a combination of dental and orthodontic treatment, and speech therapy.


Hearing Loss

The Eustachian tube connects the middle ear and the back of the throat.  It opens with swallowing.  This allows fluids to drain out of the middle ear and equalizes air pressure in the ear with the environment.  Children with a history of cleft palate often have chronic ear infections (Otitis media) because that muscle in the soft palate that is responsible for opening the Eustachian tube does not function well.  As a result, negative pressure and fluid build up in the middle ear, causing ear infections ans a conduction hearing loss.  A conductive hearing loss can affect the child's ability to develop language and even speech skills.
To avoid middle ear problems, pressure equalizing (PE) tubes are often inserted in the eardrum at an early age.  This helps to prevent fluids from building up in the ear that cause infection and hearing loss.


Velopharyngeal Dysfunction (VPD)

Also known as Velopharyngeal Insufficiency or Incompetence-VPI)
In order to close off the nose from the mouth during speech, several structures come together to achieve "velopharyngeal closure" These includes the following:
-Velum-soft palate
-Lateral pharyngeal walla-side walls of the throat
-Posterior pharyngeal walls-the back wall of the throat.

When the velopharyngeal valve closes, the speaker is able to build up air pressure and sound in the mouth to produce carious consonant sounds and vowel sounds.  Velopharyngeal closure also occurs during other activities, such as swallowing, gagging, vomiting, sucking, blowing, and whistling.
After a cleft palate repair, the velum (soft palate) may still be too short or may not move well enough to reach the posterior pharyngeal wall (back of throat).  This results in velopharyngeal dysfunction (VPD) which causes problems with speech.

Effects of Velopharyngeal Dysfunction on Speech

Velopharyngeak dysfunction can cause the following speech characteristics"
-Hypernasality (too much sound in the nose during speech)
-Nasal air emission during consonant production
-Weak or omitted consonants due to inadequate air pressure in the mouth
-Compensatory articulation productions (speech sounds produced in a different way)

Treatment of Velopharyngeal Dysfunction (VPD)

Treatment of VPD usually includes surgical intervention and speech therapy.  Prosthetic devices can also be used on a temporary or permanent basis in some cases.

Information cited : Kummer, A. 2008, Cleft Palate and Craniofacial anomolies:Effects on speech and resonance,  Delmar: Clifton Park, New York.