Photo: Rachel_S (Flickr)
Pretty much everyone has coped with a nasal voice at some point or another, whether the nasal quality was a result of a bad cold, sinus infection, or some other form of congestion.
Can You Hear Me?
Hypernasality, however, can also be the result of a more permanent disorder called velopharyngeal incompetence. What is velopharyngeal incompetence and how does it cause the voice to sound nasal, on today’s Moment of Science.
To produce most language sounds, the nasal cavity needs to be closed off from the oral cavity. Velopharyngeal incompetence means the inability to close these cavities off from one another. When the nasal cavity is not closed off the result is that when one speaks, excess air is allowed to slip into the nasal cavity and resonate there, creating an unusually nasal quality to the speech.
Why Does This Happen?
To understand how this happens it might be helpful to think of the passageway between the two cavities as a doorway. To close off a doorway you need a working door, preferably one that fits the frame just so. Normally, a mass of cells called the soft palate works with surrounding musculature to act as this door between the oral and nasal cavities.
There are a variety of reasons, though, why the soft palate door might not be able to close sufficiently. The most common cause is a cleft palate in which the soft palate itself is abnormal and will not shut. Another possibility is that the soft palate is healthy and normal, but that the doorway is abnormally large.
What can a sufferer of hypernasality do? Early detection and treatment render the best results. Treatment might include speech therapy or surgery.