Hi there! The importance of stethoscopes to medical practitioners cannot be over-exaggerated. It is an all-important tool to have in handy, especially in emergencies.
As a medical student who is still learning the trade, you may have had debates among your peers as to which stethoscope is best – the bell stethoscope or the diaphragm stethoscope.
As far as stethoscopes are concerned, there are many different ways of grouping them. You can have groups based on intended application, or even mechanism of sound reception and transmission.
With the above example, there are two major types of stethoscopes, these are acoustic and electronic stethoscopes.
With electronic stethoscopes, all the information is compiled on the chest piece with the use of special sensors and transducers. The main advantage they have is that there is minimal interference or loss of clarity during transmission. They also facilitate automation of things like calculating heart and breathing rates.
Acoustic stethoscopes on the other hand basically rely on traditional vibration and sound transmission through the reflection of the waves.
Sensitive membranes on the chest piece pick up and mimic vibrations from the skin and deeper tissues. These vibrations are passed on as waves via a tubing, designed to permit continuous reflection until the sound reaches the ears through the headset.
This traditional design is simple but very effective. It guarantees high quality and high clarity sound transmission with almost no alteration of the original sound waves.
Acoustic stethoscopes usually feature some version of the bell and diaphragm.
So, let’s get into it – the bell stethoscope vs diaphragm stethoscope.
BELL STETHOSCOPE VS DIAPHRAGM STETHOSCOPE (Differences & Similarities)
CHEST PIECE DESIGN
The bell is commonly shaped like a hollow cup or cone. Some models are covered by a membrane similar to that on a diaphragm but noticeably smaller in diameter.
The bell is made to pick vibrations from the skin which is made easy and accurate with this particular design.
With tunable stethoscopes, all you need to do to mimic a bell is release pressure applied to the chest piece.
Diaphragms on the contrary, have a plastic or fiberglass membrane stretched over the chest piece’s wide base. The diaphragm membranes are constructed from materials that are very sensitive to fine vibrations from deep tissues. These include lungs, airways and heart valves.
With tunable stethoscopes, you can achieve similar results by simply increasing the amount of pressure you apply to the chest piece.
SENSITIVITY
The bell is very sensitive to low-frequency sounds. These sounds are easily picked from the skin surface of the patient.
The Diaphragm however, is sensitive to both low and high-frequency sounds. Nonetheless, it is designed to filter out low-frequency sounds, this makes it more sensitive to high-frequency sounds.
The high-frequency sounds are enhanced as the waves vibrate against the stiff membrane. This permits accuracy and clarity in the transmission of sound from the chest piece to the tubing, and finally into the doctor’s ears.
SOUND QUALITY
The sound quality of the bell stethoscope depends greatly on the stethoscope design and features.
The bell side commonly has a more muffled sound. This means that you need to pay extra attention when you listen for heart sounds to make sure you get accurate results from your examinations.
Due to the nature and construction of diaphragm stethoscopes, the sound transmitted is usually very precise and clear.
This makes it easy to identify and separate varying sounds during the examination of a patient.
APPLICABILITY
For the bell, application is heavily dependent on the sensitivity of the stethoscope chest piece. Using bell stethoscopes, you will be listening for things like the 3rd and 4th heart sounds (S3 and S4 sounds) in the diastolic phase. These are essential when examining for conditions including congestive heart failure, dilation cardiomyopathies, and valvular regurgitation.
The diaphragm, on the contrary, is used to listen to high frequency sounds including, wheezing and lung crackles in the respiratory system and intestinal noises during abdominal auscultation.
As far as examining the heart is concerned, the diaphragm comes in useful when listening for first and second heart sounds (S1 and S2). These are important in conditions like valvular stenosis, aortic insufficiency, fistulas and many other heart anomalies that affect the systolic phase.
Which Is Better?
Truth be told, after all the above have been taken into consideration, I can say none is better than the other. Their usefulness is dependent on what exactly you want to use them for.
The great news is that you do not really have to choose between these two acoustic stethoscope designs, why should you? You can get a dual-sided chest piece or one with a tunable diaphragm. Simple!
These designs permit you to easily swap between sensitivity to high frequency and sensitivity to low-frequency sounds on the same stethoscope. Talk about multifunctional.
What Brands Of Bell & Diaphragm Stethoscopes Are The Best?
Let me start with my best pick for bell stethoscopes.
Consider this product –
FriCARE Classic Lightweight Stethoscope
This stethoscope is great for doctors, nurses, and paramedics. Oh, let’s not forget the medical students, it’s ideal for them too!
Professional and effective auscultation comes from successfully hearing the sound from your stethoscope repeatedly. This is exactly the stethoscope you need!
This stethoscope has a stronger headset than many in its class. It also has a single-frequency diaphragm, tight metal ring seal, flexible tubing design and softer ear pieces.
It is designed to provide better clarity and high level acoustic performance to help you catch the desired sounds.
With this stethoscope, you can identify S1 and S2, lung sounds, heart mumbles, carotid bruits, inside sounds, and most body sounds. It is ideal for CAN/LPN/RN/NP/APNs, travel nurses, emergency room nurses, EMT/EMS, medical assistants, nursing assistants, licensed vocational nurses, nursing students and veterinary technicians.
It is 28 inches in length, which is long enough to keep a watchful separation from the patient and effectively reduce the loss of sound transmission.
It has a smooth and flexible tubing which can seal out background noise, so it’s great for working in noisy environments.
They are comfy on the ears, as well as easy to clean. You can dip a clean white handkerchief into a simple alcohol solution and use it to clean this stethoscope.
Main Features
- It is safe to use
- It has a versatile design
- It has flexible tubing
- Very good acoustic feedback
- The tube is very durable
- Sweat, stain and oil resistant tubing material
- Easy to clean
- Comes with eartips and diaphragm replacement
- Comes with 5 year warranty
Pros
- The price is reasonably fair
- Comes with a 5 year warranty
- The tube is easy to clean, it is also sweat and oil proof
- Very durable build
- It works well in noisy areas
- It is lightweight
Cons
- It comes in just one color, black
For diaphragm stethoscope, consider this product –
Littmann Cardiology iii Stethoscope
The Littmann Cardiology iii is the only dual head Littmann stethoscope that provides accurate auscultation of both pediatric and adult patients.
It features both bell and Diaphragm technology, so it allows you detect both high and low frequency sounds. The tunable diaphragms can easily be adjusted using pressure. This means there is no need to remove the chest piece from the patient.
The diaphragm on the small side can be removed easily and can be converted to a traditional open bell.
All of the sleeves are non-chill, this ensures maximum patient comfort. The tubes contain parallel sound reducing channels which remove ambient noise.
The Littmann Cardiology iii is ideal for any medical professional that requires outstanding auditory capability in a versatile stethoscope that can be used on a variety of patients. The premium Littmann Cardiology iii is usually used by medical students, cardiologists, pediatric specialists, nurses, emergency medical technicians, emergency room doctors, and more.
Main Features
- The tunable, dual diaphragms switch between high and low frequency sounds using pressure, thereby eliminating the need to flip the chest piece.
- It is suitable for cardiology pediatric usage, as well as for adult patients
- It features 3M’s patented Snap Tight soft earpiece technology for extra comfort
- It converts to a traditional bell with included attachment
- It comes with Littmann’s five year warranty
- It comes in a variety of colors, so the more fashionable medics can have more to choose from
- It has a stainless steel chest piece
- It is latex Free
Pros
- It has soft and comfortable earpieces
- It has a 5 year product warranty
- It comes in a variety of colors
- It can be converted to a traditional bell stethoscope
- It has durable, stainless steel chest piece
Cons
- It is very pricey
Conclusion
Between the bell and diaphragm stethoscopes, we can’t say which is better. What you expect to achieve with them is what counts.
I sincerely hope this article on bell stethoscopes vs diaphragm Stethoscopes has been enlightening as well as helpful.
I also hope the two products I recommended above will meet your needs. Feel free to suggest a bell or diaphragm stethoscope if you have any in mind.
The comment section is all yours.
Good luck!