Toran K C, Vaidhya B K
Department of ENT-HNS, Kathmandu Medical College, Sinamangal, Nepal.
Kathmandu Univ Med J (KUMJ). 2010 Apr-Jun;8(30):185-9. doi: 10.3126/kumj.v8i2.3555.
Vocal polyps are the products of voice overuse, misuse and abuse as the most common causative factors. Treatment generally advised for them are voice therapy and Microlaryngeal Phonosurgery (MLPS). The improved or changed quality of voice is generally assessed perceptually and can cause intra rater variability. In this study we compared and analysed the acoustic characteristics before and after MLPS.
The purpose of the study was to acoustically determine the changes in voice quality of a group of patients before and after the surgery.
The following patients group were studied prior to and in between 3 and 4 weeks of surgery. Altogether there were 23 patients with either unilateral or bilateral vocal polyps. Voice recording and analysis were performed with Dr. Speech acoustic software (Tiger electronics, USA). The parameters analyzed were in terms of perturbation (Jitter and shimmer), harmonic-to-noise ratio (HNR) and fundamental frequency (F0).
The results showed that shimmer, HNR and F0 decreased significantly (p<0.05) following MLPS, but jitter though reduced, was not statistically significant (p = 0.694).
The acoustic output generally improved after MLPS as evidenced by decreased values of all the four acoustic parameters. The study also stress that voice quality can be improved through the phonosurgical procedures. This multidimensional voice analysis can be very helpful in our ability to provide objective clinical analysis of voices with vocal polyps, and following their surgical treatment.
声带息肉是最常见的致病因素，如过度使用、误用和滥用嗓音所产生的病变。通常建议的治疗方法是嗓音治疗和显微喉镜下嗓音外科手术（MLPS）。嗓音质量的改善或变化一般通过主观评估，这可能会导致评估者内部的差异。在本研究中，我们比较并分析了MLPS手术前后的声学特征。
本研究的目的是通过声学方法确定一组患者手术前后嗓音质量的变化。
对以下患者组在手术前以及手术3至4周期间进行研究。共有23例单侧或双侧声带息肉患者。使用Dr. Speech声学软件（美国老虎电子公司）进行语音记录和分析。分析的参数包括微扰（抖动和闪烁）、谐波噪声比（HNR）和基频（F0）。
结果显示，MLPS术后闪烁、HNR和F0显著降低（p<0.05），但抖动虽有降低，但无统计学意义（p = 0.694）。
MLPS术后声学输出总体改善，所有四个声学参数值降低证明了这一点。该研究还强调，通过嗓音外科手术可以改善嗓音质量。这种多维度的嗓音分析对于我们客观临床分析声带息肉患者的嗓音及其手术治疗后的情况非常有帮助。
