Devising an objective nasal vibration test for nasal resonatory disorders.

The present study investigates the clinical applicability of a new device, which objectively measured nasal resonating vibration via piezoelectric vibratory sensor in 10 normal volunteers, 10 patients with definite hypernasality, and 10 nasal polyposis patients. For the assessment of the hypernasality, the ratio of /ng/ to /a/ as well as the ratio of /mama/ to /papa/ passages were used. For the evaluation of hyponasality, the ratio of nasal vibration postinduced to preinduced cul-de-sac resonation was calculated. The control group showed the ratio of /ng/ to /a/ and /mama/ to /papa/ passages to be larger than 8, whereas the ratio was markedly lower in the hypernasality group. The vibratory signals of /a/ and /ng/ increased markedly in the control and the hypernasality groups after inducing cul-de-sac resonation, but the change was minimal in the hyponasality group. This new device could detect nasal resonatory disorders and readily differentiate between hypernasality and hyponasality.