If you're a nursing student or home caregiver you don't have to be too picky when purchasing a stethoscope. A good reasonably-priced, all-purpose stethoscope is great for monitoring blood pressure and heart/breath sounds.
The expensive stethoscopes are primairly for cardiologists who need to detect things like subtle heart murmurs and fine crackles in the lungs. They have a wider frequency range.


Single-Dual Head:
- The Dual Head Stethoscope is a versatile general purpose device. The diaphragm mode is used for high frequency heart sounds while the bell mode is used for lower frequency lung sounds. The user selects the bell or diaphragm by rotating the chest piece.
- The Single head stethoscope is preferred by cardiologists for monitoring heart sounds. They have a wide frequency range.
- Littmann has tunable technology single head designs where You control bell and diaphragm modes by pressure on the chestpiece rather than by turning it over.

Single-Dual Tube:
The two most popular tube designs are dual tube design and the single lumen design. The dual tube design consists of two internal tubes, each one going to a separate ear. The single lumen design allows sound to be carried to both ears through a single tube.
There are conflicting stories as to which is best:
- The sound quality is better carried in the dual tube design.
- Double-tubed stethoscopes diffuse the sound, making it harder to detect an accurate heartbeat when you take a blood pressure.
- Double tubes are more sensitive, but may rub against one another causing "squeaks" to be heard. - Some double tube models have the two tubs molded together (internal dual tube lumen) e.g. so you don't have the rubbing problem

In the tests at For US Docs 4 of the top 5 were single tube, but the Omron Sprague Rappaport rated #2 was a dual-tube.

Electronic Stethoscopes:

  • Amplifies up to 16x (24db) over traditional acoustic scopes.
    ADC Adscope 657 has 3 frequency ranges:
      - Bell (15-200Hz) for cardiac sounds
      - Diaphragm (100-500Hz) for lung sounds
      - Extended Range (15-4000Hz)
  • Acoustic stethoscope have poor amplitude and horrible fidelity. However, most electronic stethoscopes are cheap amplified implementation of the acoustic stethoscopes. Their high price is not justified by the low material cost.
  • The future belongs to a space age stethoscope using pressure sensors and advanced digital signal processing to deliver a loud clear sound.
Comments at Forums:
Stethoscopes..- EMS Responder Forums
  • Typically, it would be foolish to purchase a high dollar Master Cardiology ($170-180), Cardiology II, etc.. if you do not have the knowledge of clicks, murmurs, etc.. or at least do not plan to learn such.
  • A co-worker let me borrow his Master Cardiology. I swear I could just about hear the patient's pedal pulses while auscultating for breath sounds.
  • I recommend on whatever stethoscope you get that it has the rubber earpieces. Some of the cheap ones have hard plastic ones and they hurt my ears. Also they don't conform to your ears and can let in additional noises.
  • I'll second the Littman Cardiology III, though I myself have the Master Cardiology. Some people will say it doesn't make a difference (it's whats between the ears that counts) but after using the cheaper Littman Classic series for two years, I appreciate how much better the acoustics are in the Cardiology series.
  • Some companies (ie. littmann) don't sell stethoscopes with real bells anymore. Their master cardiology is supposed to give you low and high frequency sounds by alternating the pressure on the the single head. It works in theory, but a real bell will give you ONLY low pitched sounds, while the littmann gizmo gives either low and high pitched simultaneously or only high pitch sounds. This is a fine point, but certain heart sounds (ie. S4 vs split-S1) are distinguised from eachother by this very mechanism-thus you need a real bell and a real diaphragm.
  • I have compared the MDF® ER (797DD) stethoscope to my Littmann that I have sworn by for years and I am now using only this model, haven't touched my Littmann since I tried this. As far as price comparison, it cost approximately the same as my Littmann, but has more functions and sound quality is much better.
Some Recommendations:
Littmann Master Cardiology $200-225- The most recommended. (Not rated at ForUSDocs)
Littman Cardiology III $160-180 - got the highest rating at For US Docs
Omron Sprague Rappaport $19 - got the second best rating at For US Docs
Littmann Classic II SE $68 was rated #4

The Ultimate Acoustic Stethoscope Review at For US Docs.com
Stethoscopes - Stethoscope Suppliers and Information - Littmann - TheMedSupplyGuide.com
Stethoscope Basics - What makes a good device at kila Labs
Cardiology Stethoscopes - Electronic Stethoscopes - Stethoscope Repair at 3M - Littmann
MDF ER Premier (MDF 797DD) $100

last updated 19 May 2010