Separation of Crackles From Vesicular Sounds Using Wavelet Packet Transform

Crackles are discontinuous adventitious lung sounds with an explosive and transient character, and occur frequently in pulmonary diseases. They are the most important parameter for the diagnosis. This paper presents a new filter for automatic separation of the crackles from vesicular sounds. The proposed filter is based on the wavelet packet transform and applies two thresholds, which are defined in time-domain and frequency-domain respectively, to wavelet coefficients to achieve the separation task. This filter is more accurate and efficient compared to its rivals. Experimental results are given in detail and demonstrate its excellent performance