Which finding refers to crackling noises heard on auscultation?

• A. Rales
• B. Wheezes
• C. Rhonchi
• D. Stridor

Answer: (A)

Crackling sounds heard on lung auscultation are called rales. They are brief, discontinuous popping noises typically heard during inspiration (often at the end of inspiration for fine crackles). These sounds arise from the sudden opening of small airways or movement of fluid within the alveoli and interstitium, and they commonly appear with conditions such as interstitial edema, pneumonia, or atelectasis.

In contrast, wheezes are continuous, musical sounds caused by narrowed airways; rhonchi are lower-pitched, snoring sounds from secretions in larger airways; and stridor is a high-pitched, harsh sound heard with upper airway obstruction, usually louder on inspiration.