A New instrument for Measuring Nasal Air Current in Phonation

Abstract

The authors report here a new instrument for measuring the air current in the nasal cavity in phonation to study rhinolalia aperta. They used 2 thermisters with higher sensibility than a platinum wire hitherto used in a hot wire anemometer.(Fig. 1 and Fig. 2) They placed 2 thermisters, identical in character, in the 2 branches of the Y-shaped glass tube (Fig. 4), and recorded the changes in the Wheatstone bridge with Pen-O. S. C. and measured the air current quantitatively comparing with the standard curve (Fig. 8).
The instrument was devised so that the pen deflection might be caused only by phonation and not by breathing.
The measurement was very easy and painless even for an infant patient.