Fig. 6 shows the percentage of false positives for the main (grouped) sound classes. The lowest value of false interpretation appears for the wheezes class. This suggests that this class is the easiest to recognize because the acoustically distinctive features contained in the signal are easy to detect and interpret. There was no difference in the results for the different groups of physicians: breath sound/bronchial sound (chi2 (4) = 2.4, p = 0.671); abnormal bronchial sound (chi2 (4) = 4.5, p = 0.348); rhonchi (chi2 (4) = 2.1, p = 0.722); crackles (chi2 (4) = 1.0, p = 0.908); wheezes (chi2 (4) = 7.0, p = 0.135).