In vivo canine model was made in two mongrel dogs under the general I-V anesthesia. A vertical skin incision was made on the neck. The larynx and the trachea were dissected. Two tracheal openings were made : lower one for the insertion of the
anesthesia
tube and upper one for the delivery of air to the larynx to induce phonation. External branch of the superior laryngeal nerves and recurrent laryngeal nerves bilaterally were identified and stimulated electrically constantly.
Subglottic pressure, fundamental frequency, intensity, and open quotient were measured when the air flow rare was varying low, medium and high. Glottic resistence was calculated.
As the air flow rate increased, the subglottic pressure and the sound intensity were increased. However, glottic resistance was decreased as the air flow was increased. In falsettc register, fundamenatal frequency was increased with the increment
of air
flow, but in modal register fundamental frequency was not increased statistically significant Open quotient by the electroglottography was increased according to the increment of airflow.
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