Instrumental assessment and treatment of hypernasality, following maxillofacial surgery, using SNORS: a single case study

The super nasal oral ratiometry system (SNORS) is a commercially available system which measures both nasal and oral airflow during speech, allowing t he very rapid movement of the velum to be measured. SNORS uses a modified o xygen mask, which houses the airflow sensors and microphones, and a standar d personal computer. By calculating nasalance (the percentage of airflow th at is nasal), an estimation of velopharyngeal closure, which is independent of speech intensity, is achieved. SNORS can be used for objective assessme nt, where the subject is required to speak a number of words selected to de monstrate velopharyngeal function. SNORS also provides biofeedback, using a simple realtime display of nasal and oral airflow. Velopharyngeal insuffic iency (VPI) is the inability to make adequate velopharyngeal closure, and m ay be the result of either neurological or, as in this case, structural abn ormalities. It results in abnormal speech characteristics, such as omission s, substitutions or weak articulation of consonants, and hypernasality. T.W ., a 52 year old male, had very hypernasal speech following extensive maxil lofacial surgery, for the removal of a tonsillar carcinoma. SNORS was succe ssfully used as both an assessment and a therapy tool in the treatment of t his patient. The effectiveness of conventional speech and language therapy vs. SNORS biofeedback therapy was compared. Initially, while there was some movement of the velum, the patient could not achieve velopharyngeal closur e. Conventional therapy aimed to strengthen and improve the function of the velum and following this there was some minimal improvement: the patient c ould now achieve, but not maintain, closure. Reassessment, following a non- treatment period, showed little further change. SNORS biofeedback therapy w as then given. This raised the patient's awareness of his velopharyngeal fu nction, thus helping him to maintain closure, thereby reducing hypernasalit y. SNORS therapy proved significantly more effective than conventional spee ch and language therapy, in this case. Further intervention is outlined, an d the benefits of multiparameter assessment of speech are discussed.