Choosing a Stethoscope: A How To Guide

Earlier, I mentioned I’m in the market for a new stethoscope. Mine isn’t broken, it works perfectly well, but it’s just time. I’ve had my stethoscope for at least eight years now and, just like with my wardrobe, every so often I could use a change. But, there are so many stethoscopes on the market at so many price ranges, where do I start my search?

In a previous post, I looked at the anatomy of a stethoscope and how these auscultation devices work to give a bit of background. Today, I’ll delve into what makes one stethoscope different than another.

1. Types of stethoscopes

There are two main types of stethoscopes, acoustic and electronic. Acoustic stethoscopes are the most common and familiar. While several modifications have been made to acoustic stethoscopes in recent years to help further amplify the sound they carry, the volume of acoustic stethoscopes is still relatively low. Enter the electronic stethoscope. Electronic stethoscopes overcome the problem of low volume by electronically amplifying sound waves increasing volume ten-fold.

For most nurse nurse practitioners, an old-fashioned acoustic stethoscope will get the job done. Providers who are hard of hearing or work in a specialized field like cardiology, may find an electronic stethoscope helpful. Electronic stethoscopes may also be used in telemedicine scenarios.

2. Eartips

The eartips on a stethoscope can really make or break your day. While their function is to block out ambient noise, they must also be comfortable to wear. Most stethoscopes come with interchangeable eartips. Some providers may prefer harder eartips while others find the softer, more flexible eartips more practical.

Test a stethoscope for comfort before buying. Check to make sure the eartips conform properly to the contour of your ear canal. They should be angled forward when placed in your ear. Make sure the eartips are easy to remove for proper cleaning. Also, check to see that they adequately block out background noise so you can hear in the busy clinic or hospital environment. If you can’t hear heart sounds with a particular stethoscope, it’s not going to work.

Tip: Don’t store your stethoscope in your pocket. It can change the angle of the earpieces so they no longer fit properly.

3. Tubing

When it comes to tubing, there are a few things to consider. First, decide if a single or double tubed stethoscope is right for you. Often, a single tube system leads to better sound quality. Double tubes are technically more sensitive, but may rub together causing detectable ‘squeaks’. Some double tubed stethoscopes solve this problem by using one large tube with two inner channels rather than placing 2 tubes side-by-side.

Make sure tubing is well insulated (usually thicker). To check the tubing’s insulation, with the eartips in your ear, rub the tubing near the chest piece of the stethoscope between your thumb and finger. If the noise you hear interferes with heart or lung sounds, the tubing is poorly insulated. Move on.

Second, you must look at the length and composition of the tubing. The tubing on stethoscopes ranges from 18 to 28 inches, with most falling in the 26 to 28 inch range. While the length of tubing technically affects sound quality, this difference is thought to be so small that it is undetectable by the human ear. So, nurse practitioners should select the length of tubing based on what feels comfortable. Longer tubes drape well over the neck and may keep the provider from bending over excessively while examining patients who are lying down. Tubing should be firm but flexible. Most stethoscope tubing is now latex-free.

Tip: Polyvinyl tubing can stiffen over time with direct skin contact. Wear your stethoscope over a collar. 

4. Chest Piece

Chest pieces on a stethoscope may come in dual-head or single head models.  Dual-head models use a turnable piece including a bell and diaphragm each picking up different sound frequencies. Single head models, known as “dual frequency” or “tunable” pick up different sound frequencies based on the amount of pressure applied to the chest piece. Low frequency sounds (those detected by the bell on a dual-head) are detected on light contact with the chest, higher frequency sounds (detected by the diaphragm on a dual-head model) are heard when higher pressure is applied to the chest piece. Single head models are preferred by cardiologists. 

Chest pieces are made from stainless steel, titanium, aluminum, or plastic. A heavier, larger chest piece has a better ability to transfer sound, but in some cases may be too large, losing contact with the body. Smaller, lighter chest pieces do not carry sound as efficiently.  Some stethoscopes come with interchangeable bells and diaphragms that can be attached depending on need. For example, a small diaphragm is preferable when examining a pediatric patient. 

5. Overall Feel, Fit, and Style

Comfort is important in selecting a stethoscope. As a nurse practitioner, you will likely carry your stethoscope with you for hours each day. When purchasing a stethoscope, see how it feels hanging around your neck. If it is too heavy, it may become cumbersome or uncomfortable over the course of a long shift. If it is too long, it may get in the way. If it is too short, you may find your back aching from bending over to listen to bowel sounds. 

Companies now make stethoscopes in a variety of colors and styles. While many of these aesthetics aren’t tied to function, they can be a bright spot in your day. In choosing the color of your stethoscope, don’t forget to consider longevity. Lighter colors may become stained over time by makeup, for example. Darker colors tend to look newer, longer.

6. Practice environment

Consider your practice environment when selecting your next stethoscope. In most clinical scenarios, distinguishing a grade 3 from a grade 4 murmur isn’t necessary. But, you need to detect if a murmur does exist. If you work in a specialized clinic, you may need a more sensitive, and often more expensive, stethoscope. 

What other considerations will you take into account in selecting your next stethoscope? Is there a particular brand or model you prefer?

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