Massachusetts General Hospital, Boston.
MGH Institute of Health Professions, Boston, MA.
J Speech Lang Hear Res. 2022 Aug 17;65(8):2778-2788. doi: 10.1044/2022_JSLHR-21-00658. Epub 2022 Aug 1.
This study aimed to determine whether a simplified, and potentially more stable, acoustic-aerodynamic voice outcome ratio (ratio of sound pressure level [SPL] to subglottal pressure) is comparable to a traditional vocal efficiency measure (ratio of acoustic power to the product of average subglottal pressure and average phonatory airflow) in terms of the ability to detect change in vocal function following surgical removal of bilateral phonotraumatic lesions.
Pre- and postoperative acoustic and aerodynamic measures were analyzed retrospectively from 75 female patients who underwent surgical removal of bilateral phonotraumatic lesions. A 2 × 2 repeated-measures analysis of variance was conducted for each of three acoustic-aerodynamic voice outcome ratios-traditional vocal efficiency, an SPL-based ratio with both airflow and subglottal pressure, and a simplified SPL-based ratio with subglottal pressure only-to investigate the main effects of treatment stage (pre- and postsurgery), loudness condition (comfortable and loud), and their interaction. Post hoc paired samples tests were conducted for statistically significant interactions. The within-subject variability of the measures was assessed using the coefficient of variation.
Although exhibiting an expected main effect of loudness (higher values in the loud condition), the traditional vocal efficiency ratio did not exhibit a main effect of treatment. For both SPL-based ratios, there were significant main effects of treatment stage (higher values postoperatively) and loudness condition (lower values in the loud condition). Within-subject, postoperative changes in the two SPL-based ratios moderately correlated with one another. The simplified ratio of SPL to subglottal pressure (without airflow) exhibited the least within-subject variability relative to the other two acoustic-aerodynamic ratios.
These findings indicate that SPL-based acoustic-aerodynamic voice outcome ratios increase significantly following the surgical removal of phonotraumatic vocal fold lesions. The simplified ratio of SPL to subglottal pressure exhibits the least variability and can be easily obtained without requiring the measurement of airflow.
本研究旨在确定简化的、潜在更稳定的声学-空气动力学声能比（声压级 [SPL] 与声门下压的比值）是否与传统的嗓音效率测量（声能与平均声门下压和平均发声气流乘积的比值）在检测双侧创伤性声带病变手术后嗓音功能变化方面具有可比性。
对 75 例接受双侧创伤性声带病变手术切除的女性患者的术前和术后声学和空气动力学测量值进行回顾性分析。对三种声学-空气动力学嗓音结果比（传统嗓音效率、同时包含气流和声门下压的基于 SPL 的比值以及仅包含声门下压的简化 SPL 比值）进行了 2×2 重复测量方差分析，以研究治疗阶段（术前和术后）、响度条件（舒适和响亮）及其相互作用的主要影响。对于具有统计学意义的相互作用，进行了事后配对样本 t 检验。使用变异系数评估测量值的个体内变异性。
虽然传统嗓音效率比表现出预期的响度主要影响（响亮条件下的数值更高），但它没有表现出治疗的主要影响。对于基于 SPL 的两个比值，都存在治疗阶段（术后较高）和响度条件（响亮条件下较低）的显著主要影响。在个体内，基于 SPL 的两个比值的术后变化与彼此中度相关。与其他两个声学-空气动力学比值相比，简化的 SPL 与声门下压比值（无气流）的个体内变异性最小。
这些发现表明，在创伤性声带病变的手术切除后，基于 SPL 的声学-空气动力学嗓音结果比显著增加。简化的 SPL 与声门下压比值（无气流）具有最小的变异性，且无需测量气流即可轻松获得。
