“…Most existing projects for lung disease diagnosis using respiratory sounds follow a three-stage machine learning pipeline: 1) the preprocessing, which involves removing unwanted noise and preparing the sound data for further analysis using audio filtering and noise-reduction techniques, 2) the feature extraction, which involves extracting relevant characteristics from the preprocessed sound data using signal processing methods like spectral analysis [ [39] , [40] , [41] , [42] ], cepstral analysis [ [43] , [44] , [45] ], wavelet transforms [ [46] , [47] , [48] ], and statistical analysis [ 49 ], 3) the classification, which uses extracted features to categorize the sounds as belonging to different disease categories. Popular classifiers include K-nearest Neighbors [ [50] , [51] , [52] , [53] , [54] ], Support Vector Machines [ [55] , [56] , [57] , [58] , [59] ], Gaussian Mixture models [ 60 , 61 ], and Artificial Neural Networks [ 36 , 55 ].…”