Abstract
Changes in timber, phonation time, register and pitch of the patients' voice are examined as a routine study of the phonetic dysfunction. The timber is qualitatively assessed by mutual conversation between an examiner and a patient. The upper and lower limits of voice register are also subjectively judged by a piano. The phonation time is easily measured by a watch. In our clinics all the phonation time of voice disorders are recorded to a level recorder via a sound level meter in order to standardize its assessment, so individual phonetic functions are analyzed by their graphs displayed. Recently the authors saw two patients with laryngeal polyp or laryngeal cancer who showed no abnormalities in the routine study mentioned above and showed an abnormality only in the study of vocal intensity. To prove the relation between the vocal intensity and the other parameters in the routine study, each ten men and women, healthy volunteers were examined. The results obtained are as follows:
1. A graph, displayed the mean value of sound pressure in abscissae and the integrated value of the phonation time in ordinates on phonating, showed the constant range. The data obtained by a patient with laryngeal polyp were [absolutely beyond the normal range.
2. A graph, displayed the standard deviation of the sway of the intensity in abscissae and the mean value of the sway of the intensity in ordinates on phonating, showed the constant range. The data obtained by a patient with laryngeal cancer were absolutely beyond the normal range.
The importance of the vocal intensity as a parameter to show phonetic dysfunction is emphasized.
