The diagnostic feasibility of median frequency of lung sounds

This article evaluates the diagnostic feasibility of median frequency of lung sounds. A good correlation between median frequency and airway calibre and a good repeatability of median frequency over the same class of lung sounds do not guarantee median frequency may offer appreciable diagnostic specificity. Rather statistical significance of median frequency should be evaluated in terms of within the class similarity and between the class variability. In this article the median frequency of bronchial, vesicular, crackles, stridors and wheezes are computed using an automated PSD based method and statistical significance of the same is analyzed with Analysis of Variance (ANOVA). The experiment is conducted in Matlab®. The p-value of 0.0197 at a confidence level of 0.05 is observed. Except for the stridors and crackles the median frequency is overlapping for other classes.