bell and the diaphragm of the stethoscope

Q:  The diaphragm of the stethoscope detects best? (select one) 

A) high-frequency sounds 

B) low-frequency sounds

Answer: A

The stethoscope has two heads: Bell and Diaphragm - 

• Bell is best to detect low-frequency sounds like third and fourth heart sounds 
• Diaphragm is best to detect high-frequency sounds like pericardial and pleural friction rubs

#physical-exam

References:

1. Murphy RL. In defense of the stethoscope. Respir Care. 2008 Mar;53(3):355-69. PMID: 18291053. 

2. David L, Dumitrascu DL. The bicentennial of the stethoscope: a reappraisal. Clujul Med. 2017;90(3):361-363. doi:10.15386/cjmed-821 

3. O'Neill D. Using a stethoscope in clinical practice in the acute sector. Prof Nurse. 2003 Mar;18(7):391-4. PMID: 12674046.