Fine crackles are described as

• A. High-pitched sounds that may indicate pneumonia or pulmonary fibrosis
• B. Low-pitched sounds heard in bronchitis
• C. Continuous, low-pitched hum
• D. Grating sound from pleural surfaces

Answer: (A)

Fine crackles are short, high-pitched, discontinuous sounds heard mainly during late inspiration. They occur when small airways and alveoli reopen after being collapsed or fluid-filled, so they’re commonly linked to processes that involve the interstitium or alveolar edema. That’s why describing them as high-pitched sounds that may indicate pneumonia or pulmonary fibrosis fits best.

The other descriptions point to different adventitious sounds: bronchitis tends to produce low-pitched, snoring or rattling sounds called rhonchi; a continuous, low-pitched hum resembles a wheeze rather than a crackle; and a grating, harsh sound from pleural surfaces is a pleural rub.