Efficacy of voice laboratory in evaluation of treatment in Dysphonic patients

Document Type : Original


1 Assistant Professor of Otolaryngology

2 Medical Researcher, Assistant Professor

3 Assistant Professor of Neurology

4 Statistician, Professor- Islamic Azad University-Mashhad


Introduction: Evaluations of voice disorders include clinical assessment (subjective) and Voice Laboratory Measurements (VLM) which use objective criteria to evaluate the severity of voice disorders. The purpose of this 2 years prospective team work study (during 2004 – 2006) was to determine the efficacy of voice laboratory analysis in evaluation of treatment in dysphonic patients, in comparison with clinical (subjective) evaluation.
Materials and Methods: This study was done on 50 patients (42 males and 8 females) with voice disorders. All of the patients underwent complete ENT and neurological examinations and also complete voice lab evaluation with Visi pitch instrument and computer speech lab (CSL), both before and after appropriate treatment. Then the results of objective and subjective evaluations compared statically with the last version of SPSS software. We performed at least 5 voice parameters including fundamental frequency, phonation quotient, pitch range, percentage voiced and perturbation.
Results: Only 8 patients (16%) had statistically significant improvement in data base of voice lab parameters and the rest patients (84%) although showed some improvement but without statistically significance. Overall, the sensitivity of voice lab was 80%. Some degree of changes was observed in all of the parameters before and after treatment. In the case of perturbation (t = 3.53 and P<0.01) and jitter (t = 2.43 and P<0.05) there was significant differences with good statistical correlations.