Final answer:
A snap on releasing the nares suggests velopharyngeal incompetence, indicative of incomplete closure of the velopharyngeal mechanism and resulting in a snap sound. This can lead to hypernasality, affecting speech.
Step-by-step explanation:
If a snap is heard on releasing the nares, this means that the velopharyngeal (VP) mechanism is partially open, and the problem is probably velopharyngeal incompetence. The actual snap is indicative of the sudden release of air being trapped or momentarily held back by the incomplete closure of the velopharyngeal mechanism during speech. When the nares (nostrils) are released, this trapped air is released, creating a snapping sound. The velopharyngeal mechanism is responsible for directing the flow of air in speech. Velopharyngeal incompetence can lead to hypernasality due to inadequate closure of the velopharyngeal port, allowing air to escape through the nasal cavity during speech.