• The loudness of rhonchi gives no indication of the severity of the condition.
• Rales (sometimes called crackles):
• Probably represent opening of small airways and alveoli.
• They may be normal at the lung bases if they clear on coughing or after taking a few deep breaths.
• Pleural rub: a creaking sound caused by stiff pleural membranes such as with pleurisy.
• Stridor: harsh inspiratory sound caused by partial obstruction of a large airway.