Measurement of Pressure Effect of Articulation and Its Clinical Application

• Published in: jibi to rinsho Vol. 10; no. 1; pp. 75 - 82
• Main Author: Nishida, Yukiaki
• Format: Journal Article
• Language: Japanese
• Published: JIBI TO RINSHO KAI 10.03.1964
• ISSN: 0447-7227; 2185-1034
• DOI: 10.11334/jibi1954.10.1_75

The air pressure in the oral cavity performs an essential role in the production of consonants, especially in plosives and fricatives. The measurement of this air pressure was applied to phonetics by some investigators, Stetson (1928), Black (1950), Fischer-Jorgensen (1959) etc., but has never been applied to clinical medicine. The author decided to call this pressure “pressure effect of articulation” and reports in this paper its usefulness in phoniatrics, especially in the diagnosis of articulation defects of nasal speech. The pressure was transmitted by a polyethylene tube which was inserted in the mouth, 50cm long, with a bore of 2 mm, to the pressure transducer. The pressure recorder was constructed with the pressure transducer consisting of an RCA movable anode valve (Fig. 1) and its amplifier (Fig. 2), a DC-amplifier and Ink-oscillograph. Spoken voice and laryngeal vibration were simultaneously recorded (Fig. 3). The measurements were carried out in the sound groups of “pa”,“ba”,“ta”,“da”,“sa”, and “za”, which were pronounced in speaking pitch and moderate intensity. In normal persons, the pressure curves of various consonants displayed peculiar changes (Fig. 5) and pressure effects at least came up to 40 mmH2O in surds and 25 mmH2O in sonants. In the patients of cleft palate and paralysis of soft palate, the pressure effects were smaller or absent. Although insufficient nasopharyngeal closure and nasal escape of the pressure are plausible reasons for this phenomenon, in some cases of cleft palate the glottal stop is more important. It is distinct from the fact that the obstruction of the nose never raised the pressure effect in these cases (Fig. 6). At the glottal stop, the pressure curves were characteristic: 1) In some cases the pressure effect did not rise not only in free pronunciation but also in pronunciation with obstruction of the nose as mentioned above. 2) In other cases the pressure effect was smaller and showed abnormal curves; the curves went down temporarily in accordance with closure of the glottis (Fig. 8 and 9). From the intensity of the pressure effect and the types of curves the following 4 groups were classified. Most of the patients of cleft palate especially in adults belonged to Group I and II, and some of them who belonged to Group III get better speech by the postoperative speech training. Most of the patients of paralysis of soft palate belonged to Group III, and some of them belonged to Group IV in spite of nasal escape of the pressure.