Nasalance
Encyclopedia
Nasalance is a measure of the degree of velopharyngeal
opening in voiced speech formed by computing the ratio of the amplitude of the acoustic energy at the nares, An, to amplitude of the acoustic energy at the mouth, Am. The term nasalance usually refers to this ratio as a percentage:
and thus may be more properly expressed as Percent Nasalance. The term originated in the work of Fletcher and his associates and is now implemented in a number of commercially available devices (Kay-PENTAX Nasometer and Glottal Enterprises NVS System). There are small differences in the manner in which nasalance is computed in various devices, and differences in the manner in which the oral and nasal acoustic energies are separated physically, as by a hard separator plate held against the upper lip vs. a two-chamber pneumotachograph mask. However, there have been no conclusive studies of the effect of these differences on a relevant underlying physical variable, such as the area of the velopharyngeal
opening.
Velopharyngeal inadequacy
Velopharyngeal inadequacy is a malfunction of a velopharyngeal mechanism.The velopharyngeal mechanism is responsible for directing the transmission of sound energy and air pressure in both the oral cavity and the nasal cavity. When this mechanism is impaired in some way, the valve does not fully...
opening in voiced speech formed by computing the ratio of the amplitude of the acoustic energy at the nares, An, to amplitude of the acoustic energy at the mouth, Am. The term nasalance usually refers to this ratio as a percentage:
and thus may be more properly expressed as Percent Nasalance. The term originated in the work of Fletcher and his associates and is now implemented in a number of commercially available devices (Kay-PENTAX Nasometer and Glottal Enterprises NVS System). There are small differences in the manner in which nasalance is computed in various devices, and differences in the manner in which the oral and nasal acoustic energies are separated physically, as by a hard separator plate held against the upper lip vs. a two-chamber pneumotachograph mask. However, there have been no conclusive studies of the effect of these differences on a relevant underlying physical variable, such as the area of the velopharyngeal
Velopharyngeal inadequacy
Velopharyngeal inadequacy is a malfunction of a velopharyngeal mechanism.The velopharyngeal mechanism is responsible for directing the transmission of sound energy and air pressure in both the oral cavity and the nasal cavity. When this mechanism is impaired in some way, the valve does not fully...
opening.