A simple nasal anemometer for clinical purposes.

There is a need for clinical methods which give more direct information about the behaviour of the velopharyngeal mechanism in natural speech than do the examination methods normally applied to patients suffering from velopharyngeal insufficiency. One possibility is the recording of nasal airflow in order to detect nasal emission of air. The purpose of the present study is to examine the qualities and the characteristics of a simple and cheap nasal anemometer. As this type of flowmeter is considered less reliable than most other flowmeters, its limitations must be clearly understood and accounted for in drawing conclusions. Therefore, nasal airflow in speech obtained with this flowmeter is discussed in relation to nasal airflow obtained by the more reliable pneumotachograph and in relation to nasal airflow data found in the literature. The tests made here suggest that, at least for the type of speech material and measurements used in the present study, reliable nasal airflow data can be obtained by the anemometer.