Chest Piece Of A Stethoscope || Working ,Usage and Problems

To use a stethoscope effectively, one should understand its parts and function to make the diagnosis easy and effective. Stethoscopes have several features, and each part has different functionality. But all the parts are designed to allow the user to hear the tiny sounds of the patient’s body. 

However, the purpose of this article is to make you knowledgeable about the chest piece part of the stethoscope and how it works. Moreover, I will give you all the related information you need to know about the chest piece.

What Is The Chest Piece Of A Stethoscope?

Stethoscopes have chest pieces, also known as heads, which conduct sound. This is the part that touches the patient’s skin to listen to body sounds. Thanks to technological advancements, many stethoscopes can also transmit sounds through clothing, bandages, blankets, and even animal fur. The chest piece comprises three parts.

  1. Stem
  2. Diaphragm
  3. Bell

Single-Sided And Double-Sided Chest Pieces

Depending on the model, it is possible to have a stethoscope with either one or two-sided chest pieces. Chest pieces with two sides have both a bell and a diaphragm, whereas a single-sided chest piece has only a diaphragm.


The single-sided chest piece allows doctors and nurses to listen to high and low frequencies by varying the diaphragm pressure. Some diaphragms can function as both a bell and a diaphragm based on their adjustable or pressure-sensitive nature. 

Each Design Has Its Advantages

Stethoscope chest piece designs vary naturally depending on the model. However, different designs provide unique advantages that allow healthier providers to amplify sound and have an effective listening experience.

Moreover, the bells and diaphragms of modern stethoscopes are typically covered in a plastic disk enclosed by a metal base. 

By placing the disk against the patient’s skin or clothing, the plastic disk will vibrate when the patient’s body makes sounds. Vibrations from the device are responsible for creating the sounds you hear.

Diaphragm Of Chest Piece

Due to its larger diameter, the diaphragm picks up noise with a higher frequency, such as breathing sounds. It is best to utilize the diaphragm to diagnose adult patients and detect specific human body conditions. 

Bell Of Chest Piece

 Those picking up lower frequency noises like heart murmurs, on the other hand, use the bell, which is much smaller. Bells are also used to listen to more minor pediatric patients’ breath sounds since the smaller size allows them to be heard more clearly.


The stem is the metal piece attached to the tube to connect the diaphragm and bell. You can rotate the head of your stethoscope using this component to alternate between using the bell and diaphragm if you own a dual-sided stethoscope.

Hypoallergenic and non-chill construction

In order to increase patient comfort, some companies sell stethoscopes with diaphragms and bells made of hypoallergenic and non-chill substances. In addition to metal chest pieces, acrylic head stethoscopes are also available, which are fantastic for blocking out external sounds.

What Is The Purpose Of A Chest Piece?

Stethoscopes’ chest pieces play an essential role in the instrument’s acoustic performance since it is meant for catching, and transferring sounds between the body and the headset.

Identify Various Sounds From The Body Of The Patient

Chest pieces are used for listening to the patient’s sounds by placing diaphragms or bells on his or her chest, back or abdomen, and much more. This permits the device to detect heartbeats, lung sounds, arterial conditions, and other human sounds.

As previously noted, pressure is applied to the chest piece to adjust the frequency of the bell and diaphragm. Therefore, healthcare specialists are able to determine the seriousness of sounds more accurately.

Place On Bare Skin For Clear Sounds

In general, chest pieces work best when they are applied directly to a patient’s skin in the right place. Nonetheless, there is stethoscope technology that is strong enough to penetrate layers of clothing.

Electronic stethoscopes, for example, amplify sound to help medical professionals hear even the faintest sounds of the patient’s body. A medical professional in the field of cardiology or emergency care needs to have this type of stethoscope.

Instructions For Using A Chest Piece

A Littmann stethoscope with a traditional combination chest piece needs to be opened to access its side. The chest piece stem must be held in one hand while rotating it with the other hand until you hear the click sound.  

How To Change Frequencies Of A Tunable Chest Piece?

 Thanks to its patented tunable diaphragm, you can listen to low-frequency and high-frequency sounds using either side of the Littmann Cardiology III Stethoscope. 

Low frequency: 

The traditional bell mode of listening to low frequencies is achieved by lightly using the bell on the skin.

High frequencies:

 To listen to higher-pitched sounds (traditional diaphragm mode), the user should push hard on the chest piece until it contacts the skin.

By alternating light and firm pressure on the chest piece, you can listen to low- and high-frequency sounds without removing and repositioning the chest piece.

How To Remove The Diaphragm And Clean The Chest Piece?

The diaphragm should be facing up, so grasp the rim with the index and middle fingers of both hands. Roll the rim away from the edge of the chest piece, and release. 

Then, clean the parts with soapy water or alcohol after removing the diaphragm from the rim. Also, you can clean chest piece surfaces with soap and water or alcohol. Reassemble the chest piece after thoroughly drying everything. 

Furthermore, 70% isopropyl alcohol may be used to disinfect a stethoscope if necessary. Following are some points to avoid when cleaning a stethoscope, which most users do.

  • Dipping the stethoscope in any kind of solution.
  • Cleaning the device with a hand sanitizer
  • The use of an autoclave for sterilization

Thus, you should not make these mistakes if you want to avoid damaging your stethoscope.


Photo of author

Muhammad Bilal Qayyum

MBBS from Taishan Medical University and currently working in Bahawal Victoria Hospital. The blog is a great resource for both novices and experienced users when it comes to stethoscopes. As I studied and practiced, I evaluated various models on the market, which led me to become an expert in stethoscopes.

Leave a Comment