Abstract
Subglottic pressure was registered on oscillographic paper during utterance of Japanese monosyllables. A pressure transducer was connected to the subglottic space with a puncture needle or a tracheal cannula. It was hooked up with a carrier amplifier which was then coupled with a galvanic oscillograph. The audio signal was recorded on both a tape recorder and another channel of the oscillograph simultaneously.
The results are summarized as the followings:
1) In normal subjects the subglottic pressure began to rise prior to the onset of the audio signal. The maximum pressure was from 10 to 18cm H20. No marked fluctuation or sudden change in the pressure was found except for a temporary drop for the transient from voiceless consonant to vowel.
2) In pathological cases the subglottic pressure was often fluctuated. Not infrequently, it continued elevating until the end of syllable.
3) The maximum pressure in recurrent laryngeal nerve paralysis varied considerably from case to case.
4) The subglottic pressure was extremely high in case of laryngeal cancer, especially in case with extensive invasion of carcinoma which involved the vocal cord Cs).
5) The pressure was inordinately great also in cases of partial laryngectomy where the vocal cord had been replaced with scar tissue. The size of pressure depended upon the type and extent of surgery.
6) Skillful users of esophageal speech kept the pressure below the neoglottis without remarkable alteration throughout, whereas untrained speakers presented an initial high pressure followed by a sudden drop-out.
