How is normal speech produced?
Speech results from a sequence of events which includes producing airflow out of the lungs (exhaling), a vibration of the muscles of the voice box (vocal cords), and regulating the amount of resonating air allowed to escape the body through the mouth and/or nose. The air escaping the mouth can then be manipulated by the lips, teeth, and tongue to produce a specific speech sound.
What is the difference between hypernasal and hyponasal speech?
There is often a lot of confusion between the terms hypernasal as opposed to hyponasal speech. Both of these speech disorders are known as disorders of resonance (problems regulating the amount of air leaving the mouth and/or nose).
Hyponasal speech is the sound of speech that results from too little air escaping through the nose (sounds like talking with a stuffy nose). It would be hard to normally pronounce the letter “m” for example. The most common reason for this type of speech are enlarged ADENOIDS that block the air passage to the nose and can be corrected with ADENOIDECTOMY.
Hypernasal speech is the sound of speech that results from too much air escaping through the nose while talking. There are certain letters and sounds that should not have air escaping through the nose during speech. Examples of these are vowels, or letters like “s”, “b”, and “k”. To keep air from passing through the nose, the roof of the mouth (velum) must touch the back of the throat (pharynx). If these do not touch correctly, resulting in a complete seal of this area, too much air is allowed to pass through the nose and hypernasal speech results. This is known as velopharyngeal incompetence or VPI .
What are the causes of hypernasal speech?
Hypernasal speech can be caused by anything resulting in velopharyngeal incompetence. Clefting (splitting) of the roof of the mouth (CLEFT PALATE), a palate that is too short, or the inability to move muscles involved with closure of the velopharyngeal complex (as in cerebral palsy) can cause hypernasal speech. Less commonly, hypernasal speech can occur in someone with an undiagnosed problem of the palate muscles, especially if an ADENOIDECTOMY is performed.
How is hypernasal speech evaluated?
Hypernasal speech may be first noted by the parent, primary care doctor, or teacher. The child should then be evaluated by a speech-language pathologist (a specialist in speech problems). A speech pathologist is able to evaluate and identify abnormal speech patterns. The speech pathologist will also look for obvious abnormalities in the mouth and listen with special instruments to the amount of airflow passing through the nose.
Instruments using computer analysis of airflow (nasometry) may also be used during an evaluation to detect abnormalities, as well as follow progress of therapy. If hypernasal speech is identified, an x-ray study is done to help localize the problem area and referral to an ear, nose and throat specialist occurs.
What will an ear, nose and throat specialist do?
The ear nose and throat specialist is an expert in evaluating and treating hypernasal speech. We have the ability to look at your child’s anatomy to determine the cause of hypernasal speech.
This is done through nasal endoscopy, a procedure that uses a tube to look closely at the anatomy inside the nose and deeper in the throat. Nasal endoscopy is used with the speech pathologist in attendance. Along with the nasometry and x-ray results, the findings on nasal endoscopy will allow a plan of treatment to be developed for your child’s hypernasal speech. This treatment plan, either medical or surgical therapy, will then be discussed with you.
What is the treatment for hypernasal speech?
Speech therapy may be all that is necessary for some forms of hypernasal speech. This type of therapy may take several months or years to achieve the desired result. However, if therapy does not result in resolution of the hypernasal speech, or if the defect is very large, surgical correction may be necessary. This generally involves three basic methods:
- Augmenting (adding to) the back of the throat, to make closure easier,
- Making the velar port (back of nose) smaller, or
- Lenthening or repairing the palate (roof of mouth). Please see PALATOPLASTY for more information.