Müsebeck K, Rosenberg H
Laryngol Rhinol Otol (Stuttg). 1983 May;62(5):226-31.
The phonatory airflow can be measured by means of a hot wire tube placed in the supraglottic space without tying down the tongue. The velocity of airflow above the glottis reaches values around c = 50 to 150 cm/s. The variations in airflow oscillations were recorded. The voice of the person under examination was picked up by a condenser microphone (Bruel & Kjaer No. 2112). According to D'Alembert's wave equation, the sound intensity is related to the velocity of the phonatory air stream. The validity of this statement has been confirmed by repeated testing. The fundamental frequency of voice and of the airflow were analysed synchronously by means of the Nicolet analyser. The air consumption is not utilized for sound production in phonation by breathing. A "hard" or "pressed" voice is associated with diminished or irregular air consumption. The method can be employed in assessing the conditions of phonetic airflow in normal and dysphonic voices.