[Three kinds of speech evaluation in maxillectomy patients during the fabrication process of a hollow-type obturator]

Speech evaluation is essential to the rehabilitation of maxillectomy patients. A speech intelligibility test has been frequently used for the evaluation because of its simplicity. However, the test needs human listeners and this has been a shortcoming of the test. Thus, objective evaluation methods have been discussed. One of them is formant analysis for vowel evaluation and another is psychoacoustic analysis for consonants. In this research, to evaluate the speech in five maxillectomy patients, the F2-range was examined as formant analysis and the sharpness of /sa/ was examined as psychoacoustic analysis, in addition to the speech intelligibility test, during the fabrication process of a hollow-type obturator. The objective evaluation of patients' speech was effectively performed using those three methods. The F2-range was larger, the sharpness of /sa/ was higher and the speech intelligibility was higher when patients wore an obturator compared to when patients did not wear an obturator. The difference in speech when changing the types of obturator was not clear. The method and the findings are important for future research in this field, since speech is one of the important factors in maxillofacial rehabilitation.