Wheezing
When a person exhale from his mouth and air is pushed through narrow airways in the lungs, a whistling or musical sound is produced which is called wheezing.
In people with COPD, excess mucus obstructing the airways is often the main culprit. Muscular tightening also narrows the airways making condition even worse for the patient. Visit your doctor immediately if you experience any whistling sound being produced inside your chest.