Jiang J, O'Mara T, Conley D, Hanson D
Department of Otolaryngology-Head and Neck Surgery, Northwestern University Medical School, Chicago, IL 60611, USA.
Laryngoscope. 1999 Mar;109(3):425-32. doi: 10.1097/00005537-199903000-00016.
OBJECTIVE/HYPOTHESIS: Most methods to measure phonation threshold pressure (PTP) are clinically impractical because they are invasive. This report concerns an airflow interruption system developed to allow noninvasive estimation of (PTP) at different levels of vocal intensity. An estimation of PTP was made for normal subjects with normal larynges and no voice complaints and for individuals who had dysphonia associated with vocal polyps to compare the estimated minimal pressure across the glottis that was required to sustain phonation in the two conditions.
This was a methodological study designed to measure an unanticipated PTP from a subject.
Subjects sustained a constant tone and the airflow was directed into a section of pipe with an airtight mask over the mouth and nose. The airflow, intramask pressure, and intensity of the acoustic output were recorded. A PTP was predicted from a difference between an estimate of the subglottal pressure and the vocal tract pressure at the point that phonation ceased after interruption of airflow. Eleven control subjects and 13 patients with vocal fold polyps were studied. In each population there were eight men and five women. The individuals in the group with vocal fold polyps averaged 39 years of age, and the control subject group averaged 49 years of age. Normal subjects produced a steady vowel /a/ at 75, 80, and 85 dB. Patients with polyps were unable to sustain phonation at these levels but were able to produce phonation at 65, 70, and 75 dB. The validity of the system was tested using a laryngeal model and in a patient with a normal larynx and voice who had a tracheotomy (placed for sleep apnea syndrome) which allowed direct measurement of subglottal pressure.
The measured mean PTP levels (with standard deviation [SD]) for the control subjects were 2.38 (1.273), 2.67 (1.879), and 2.98 (2.23) cm H2O at 75, 80, and 85 dB, respectively. The measured mean PTP levels (with SD) for the patients with polyps were 4.79 (2.67), 5.85 (2.34), and 7.37 (3.26) cm H2O at 75, 80, and 85 dB, respectively. The differences in mean PTP between groups at 75, 80, and 85 dB were significant at P = .013, P = .017, and P = .010, respectively.
The estimations of PTP for patients with vocal fold polyps were significantly higher than for the control subjects at three phonation levels.
目的/假设：大多数测量发声阈压力（PTP）的方法在临床上不实用，因为它们具有侵入性。本报告涉及一种气流中断系统，该系统旨在实现对不同发声强度下的PTP进行非侵入性估计。对喉部正常且无嗓音问题的正常受试者以及患有与声带息肉相关的发声障碍的个体进行了PTP估计，以比较在两种情况下维持发声所需的估计的声门最小压力。
这是一项旨在测量受试者意外PTP的方法学研究。
受试者持续发出恒定音调，气流通过口鼻上的气密面罩导入一段管道。记录气流、面罩内压力和声输出强度。在气流中断后发声停止的点，根据声门下压力估计值与声道压力之间的差值预测PTP。研究了11名对照受试者和13名声带息肉患者。每组中有8名男性和5名女性。声带息肉组个体的平均年龄为39岁，对照受试者组的平均年龄为49岁。正常受试者在75、80和85分贝时发出稳定的元音/a/。息肉患者无法在这些水平维持发声，但能够在65、70和75分贝时发声。使用喉部模型以及一名喉部和嗓音正常但因睡眠呼吸暂停综合征行气管切开术（可直接测量声门下压力）的患者对该系统的有效性进行了测试。
对照受试者在75、80和85分贝时测得的平均PTP水平（标准差[SD]）分别为2.38（1.273）、2.67（1.879）和2.98（2.23）厘米水柱。息肉患者在75、80和85分贝时测得的平均PTP水平（标准差）分别为4.79（2.67）、5.85（2.34）和7.37（3.26）厘米水柱。两组在75、80和85分贝时的平均PTP差异分别在P = 0.013、P = 0.017和P = 0.010时具有统计学意义。
在三个发声水平上，声带息肉患者的PTP估计值显著高于对照受试者。
