There are three abnormal lung sounds that can be heard during respiratory problems, they are crackles, rhonchi and wheezes.Crackles are high-pitched sounds heard during inspiration. It resembles the cracking or rattling sounds.Rhonchi, on the other hand, are rumbling course sounds heard during inspiration or expiration. It can be cleared when coughed out or when phlegm is suctioned out.Wheezes are musical-like sounds heard during inspiration or expiration. It resembles whistling sounds and it can be heard louder during expiration.