Resonance 

Resonance is the quality of the voice that is determined by the balance of sound vibration in the mouth, nose, and throat during speech. Resonance disorders may be related to too much airflow leaving the nose while speaking (hypernasality), or not enough airflow leaving the nose while speaking (hyponasality). Disorders such as Cleft Palate, Cerebral Palsy or hearing loss can also cause resonance disorders.