What is resonance?
Resonance is the quality of the voice that comes from sound vibrations in the throat, mouth and nose. Resonance varies by speech sound and by language and dialect. When we talk, we take a breath and speak with the air that leaves our mouths. The air passes through the vocal cords, where it vibrates. The air continues to the mouth and nose, and they shape it into speech sounds. Parts of your child’s body work together to make normal-sounding resonance. These include the back part of the roof of the mouth (soft palate) and the throat (pharynx). When your child makes most sounds, the soft palate and pharynx close off the passageway to the nose so they can speak through their mouth. This passageway is called the velopharyngeal port. It stays open for nasal sounds (m, n, ng) so the sound comes out through the nose.
What are resonance disorders?
A resonance disorder occurs when there is a change in the way air and sound move through your child’s mouth, nose and throat. This may happen because of an opening (space in the anatomy), an obstruction (blockage), or inconsistent movement of the velopharyngeal port. There are four types of resonance disorders: hypernasality, hyponasality, cul-de-sac resonance and mixed resonance.
Causes of resonance disorders
Velopharyngeal dysfunction (VPD) may cause hypernasality. The Velopharyngeal Dysfunction Program is a clinic at Children’s Hospital of Philadelphia (CHOP) with a team of experts who treat patients with VPD. VPD may result from:
- Cleft palate
- Submucous cleft palate
- Adenoidectomy or tonsillectomy
- Cancer of the soft palate (palatal tumors)
- Disorders associated with genetic syndromes, such as:
- VPD may also be present from birth (congenital). The size and shape of the throat and roof of the mouth (palate), or the way these structures can move, can cause VPD.
- Large tonsils or glands between your child’s airway and the back of their throat (adenoids)
- Allergies or common colds
- Deviated septum
- Small mouth opening
- Large tonsils or adenoids
- Difficulty hearing speech sounds
- Problems with motor planning for speech. This can cause abnormal or uncoordinated opening and closing of the soft palate, nose and mouth.
- Difficulty hearing speech sounds
- Hypernasality related to congestion, nasal obstruction, or corrective palate surgery that doesn’t go away
Symptoms of resonance disorders
Resonance disorders can range from mild to severe. Each type of resonance disorder has its own set of symptoms:
- Hypernasality occurs when too much sound resonates (vibrates) in your child’s nose while they are speaking. Your child may sound as if they are “talking through their nose.”
- Hyponasality occurs when not enough sound resonates in your child’s nose while they are speaking. Your child may sound “stuffy” or congested.
- Cul-de-sac resonance occurs when sound is trapped in your child’s throat or nose while they are speaking. Your child's speech may sound muffled, as if they are “mumbling,” or not speaking up.
- Mixed resonance occurs when a combination of too much and too little sound resonates in your child’s throat, mouth, and nose while they are speaking.
Your child’s speech may be difficult for others to understand, especially in severe cases.
Testing and diagnosis for resonance disorders
Here at Children’s Hospital of Philadelphia (CHOP), there are three specialists who will diagnose your child’s resonance disorder:
- Speech-language pathologists (SLPs)
- Plastic surgeons
- Ear, nose and throat doctors (ENTs) who specialize in the palate
During a speech and language evaluation, our SLP will check your child’s resonance and how they make speech sounds (articulation). The evaluation activities may include:
- Talking to your child.
- Asking your child to repeat specific words, phrases and sentences.
- Performing an oral examination. This includes looking inside your child’s mouth as they move their lips and tongue and make sounds.
At a speech and language evaluation, our SLP may refer your child to the Velopharyngeal Dysfunction Program. At VPD clinic, an SLP and a plastic surgeon will conduct a speech evaluation and a physical examination of your child's velopharyngeal area.
If needed, your child may participate in an imaging procedure to watch the nose, throat and mouth as they talk. This may include either of these procedures:
- Video nasoendoscopy – where we place a small camera through your child’s nose to visualize the velopharyngeal mechanism from above while your child is speaking
- Video fluoroscopy – where a radiologist places a solution to help create a clear picture (barium) inside your child’s nose, then they take video while your child is speaking.
These procedures can help identify the cause of a resonance disorder. They can guide our team in selecting the best possible treatment options for your child.
Treatment for resonance disorders
At CHOP, we use two primary treatments to help your child with resonance disorders: speech therapy and speech surgery.
The goal of speech therapy is to help your child learn to make sounds accurately in their mouth. Therapy for resonance disorders involves specialized techniques. Your child may get therapy at CHOP. Or your child may work with a local SLP, with a CHOP SLP providing consultation. Speech therapy can improve speech if your child’s resonance disorder has no structural cause. Your child would need speech surgery to make a structural correction.
Speech surgery may be recommended to correct your child’s hypernasality when speech therapy cannot. Your child’s surgeon will collaborate with other specialists at CHOP to decide the best treatment option for your child’s unique condition. Your child may need speech therapy before and after the procedure. This will help your child’s progress and recovery.
Reviewed by Arielle Berne, MA, CCC-SLP