Nasality (or resonance) refers to the quality of the voice that is determined by the balance of sound vibration in the oral, nasal, and pharyngeal cavities during speech. Abnormal resonance can occur when there is obstruction in one of the cavities, causing hyponasality, or when there is velopharyngeal dysfunction, causing hypernasality. This category should only be assigned when hyponasality or hypernasality is outside the limits of normal variation and results in reduced intelligibility and significantly affects communication.