Crackle Pitch Rises Progressively during Inspiration in Pneumonia, CHF, and IPF Patients

Figure 1

A time amplitude plot of inspiratory lung sounds recorded from a patient with pneumonia. Channels 1 to 7 were recorded from the right lung, channels 9 to 15 were recorded from the left lung, channel 8 was recorded from the heart (not used for crackle analysis), and channel 16 was recorded from the trachea (not used for crackle analysis). A black border indicates crackle families, mother crackles are marked by a star “*”, crackle pitch is shown on top of each border. Thick vertical lines indicate the boundaries between early, mid-, and late-inspiration.