Children with resonance disorders (hypernasality, hyponasality and cul de sac resonance) or velopharyngeal dysfunction can present challenges for speech-language pathologists (SLPs) in all settings. The purpose of this article is to present current, practical information for practicing SLPs who frequently or occasionally see individuals with a history of cleft palate or abnormal resonance.
Normal Resonance and Velopharyngeal Function
Resonance, as it relates to speech, is the modification of the sound that is generated by the vocal folds as it vibrates (resonates) through the cavities of the vocal tract (pharynx, oral cavity, and nasal cavity). The type and quality of resonance is determined greatly by the function of the velopharyngeal valve. As shown in Figure 1, the velopharyngeal valve is open for nasal breathing and remains open for the production of nasal sounds (m, n, L).
Figure 1. Velum at Rest during Normal Nasal Breathing
From Cleft Palate and Craniofacial Anomalies Effects on Speech and Resonance (2nd ed.) by A. Kummer, 2008. Reprinted with permission of Delmar Learning, a division of Thomson Learning: www.thomsonrights.com. Fax 800-730-2215.
When oral sounds are produced during speech, the velopharyngeal valve closes, thus directing both sound energy and airflow from the pharynx into the oral cavity (see Figure 2). Because airflow and sound travel in a superior direction from the lungs to the oropharynx, the velopharyngeal valve must close completely to prevent speech distortion.
Figure 2. Velum Elevated to Achieve Velopharyngeal Closure
From Cleft Palate and Craniofacial Anomalies Effects on Speech and Resonance (2nd ed.) by A. Kummer, 2008. Reprinted with permission of Delmar Learning, a division of Thomson Learning: www.thomsonrights.com. Fax 800-730-2215.
Speech Therapy for "Cleft Palate Speech" and Sequelae of Velopharyngeal Dysfunction [Video Course]
