  Patients with respiratory conditions typically exhibit adventitious
respiratory sounds, such as wheezes. Wheeze events have variable duration. In
this work we studied the influence of event duration on wheeze classification,
namely how the creation of the non-wheeze class affected the classifiers'
performance. First, we evaluated several classifiers on an open access
respiratory sound database, with the best one reaching sensitivity and
specificity values of 98% and 95%, respectively. Then, by changing one
parameter in the design of the non-wheeze class, i.e., event duration, the best
classifier only reached sensitivity and specificity values of 55% and 76%,
respectively. These results demonstrate the importance of experimental design
on the assessment of wheeze classification algorithms' performance.
