• These are intermittent "bubbling" sound.
• Laennec compared these sounds to the sound of water being poured from a bottle.
• They are caused by airway opening and secretions in airways.

As noted on the previous display coarse crackles are in general lower pitched, less intense and of longer duration than fine crackles. The most common conditions associated with coarse crackles are congestive heart failure and pneumonia.