The Creation Wiki is made available by the NW Creation Network
Watch monthly live webcast - Like us on Facebook - Subscribe on YouTube


From CreationWiki, the encyclopedia of creation science
Jump to: navigation, search

The Stethoscope is a medical tool that is used by doctors to listen to internal sounds coming from the lungs, heart murmurs, the stomach, and even the intestines. Although there are many useful and beneficial medical tools out there, the stethoscope is, by far, one of the most important additions to the medical world. Over time, the stethoscope has become more and more technologically advanced. The stethoscope was invented because a man named René Théophile Hyacinthe Laennec thought that distance from the patient while listening to a patient's heartbeat would be a good thing. It started out as a long paper roll but was later made with metal or brass.[1] It has three different essential parts that all work together harmoniously to intensify a patient’s internal sounds. The stethoscope has many advantages but there are also disadvantages. Ultimately, the invention of the stethoscope has improved medical diagnosis and has helped to predict internal problems before they have a chance to become too serious.


René Théophile Hyacinthe Laennec using the first stethoscope that he invented.

In 1816, a doctor named René Théophile Hyacinthe Laennec was getting the sense that he should think up more appropriate way to listen to patients’ hearts. He took into account that the age and gender of the patient could become very awkward because, at the time, the process was very hands-on and could make patients uncomfortable.[1] Therefore, Laennec listened at the end of a long, wooden stick to noises coming from a needle grazing across it. This was when he realized that he could listen to a patient’s heartbeat using a long, hollow object. He began using a lengthy roll made out of paper.[2] It took him a while to think of an efficient name for his creation. He juggled between names like; “petrolique”, “sonometer”, and “medical cornet”. Laennec finally stumbled across a Greek word that means to look inside the chest: stethoscope.[1].

About twenty-five years later, a man by the name of George P. Cammann recreated the stethoscope to make it more durable. He placed an earpiece at the ends of the stethoscope so that the sound could reach both ears. A Harvard professor, Dr. David Littmann, brought many more improvements to Laennec’s original invention. This didn’t take place until about a decade and a half after.[3]Although Littmann helped to make it happen, the very first stethoscope manufactured and pieced together by Laennec was a cylinder, the diameter was two centimeters long, and the overall length of the structure was about thirty centimeters. Doctors began to utilize stethoscopes as early as 1820. The stethoscope was later made with different matter such as: brass, silver, glass, and ivory. Also, for extensively contagious patients, doctors can choose to use a stethoscope that is 35 cm; to keep their distance.

How It Works

A close up picture of the structure of a stethoscope.

The stethoscope is composed of three major parts. The first part is the chest piece. The chest piece is not just one piece, it has two parts-the diaphragm and the bell. The diaphragm contains a plastic piece that resides within the silver metal piece that touches the patient. The second piece, the bell, is pretty self-explanatory. It is shaped like a hollow bell and detects the sounds at a lower pitch, while the diaphragm identifies the high-pitch noises. The second major parts of the stethoscope are the tubes, primarily made of rubber. This is a very important aspect. It serves to connect the chest piece to the head set. Although keeping the parts together helps tremendously, the tubes carry the noises picked up by the diaphragm and the bell to the headset.The third key component is the headset. The rubber tubes that carries the sound connects to the metal tubes. These metal tubes then direct to sounds to the ears. The eartips at the end of the metal tubes consist of rubber to hinder the surrounding noise that could affect the doctor’s interpretations of the sounds.[4] Eardrums vibrate when sound waves pass through them, stethoscopes work in a similar way. Sound waves that are caused by whatever is occurring within the patient’s body cause the diaphragm of the chest piece to vibrate. These vibrations then move through the rubber tubes, through the metal tubes, and then finally reach the doctor’s ears. The small bell detects the sounds at a lower pitch because the diaphragm cannot identify such low pitch. The low-pitch vibrations cause the patient’s skin to vibrate, which is where the bell detects the sound. [5]


Snapshot of a doctor utilizing the stethoscope on a patient.

The stethoscope has proved itself to be a very beneficial addition to medical diagnostics. With the help of a stethoscope, doctors are able to listen closely to what is going on within their patient’s body. Sounds coming from the stomach, lungs, and even some of the lower intestines can be distinguished. These sounds can ultimately result in a diagnosis that could potentially save someone’s life.[6]

Another advantage that the stethoscope offers is the fact that it doesn't cause the patient to be in pain. Unlike having to get punctured by a needle when getting a shot or pounded on the knee with their hammer, stethoscopes are painless and just require skin contact. Some stethoscopes, however, are so advanced that they do not even need contact with skin, it can detect the sounds through clothes. The stethoscope is also very uncomplicated, simple to operate, and quick. This medical tool requires little to no training. One only needs to have little knowledge about where to place the diaphragm of the stethoscope in order to hear sound. Also, the stethoscope is constructed in such a way that a doctor is able to make out internal sound a lot better than just simply using his or her fingers.[7] One may presume that one would be able to hear the sounds going on within the chest better if their ear is touching the patient but this isn’t true. The sounds that come through a stethoscope that is more than two feet away are the most distinctive and perceivable. [5]

Electronic stethoscopes have many advantages as well. They are able to amplify noise a lot better than a regular stethoscope. Some electronic stethoscopes have their own software for the computer so it is easier to distinguish the sound waves.[8]Electronic stethoscopes are also able to detect the quiet humming sounds coming from the heart. These stethoscopes can also record the sounds detected and can also be played back if the doctor desires to listen again carefully. Because of the electronic stethoscope is so advanced, it can also transport the information to a computer portable electronic device. [9]


Although the stethoscope brings many benefits to the world of medicine, there are also disadvantages and inaccuracies. One disadvantage would be the risk of the user losing his or hers hearing. The stethoscope’s ability to magnify and amplify sound could backfire. Suppose one held the tool to a loud noise or something occurred that caused a loud noise, that person’s hearing would be seriously affected. The spreading of germs could also be another issue. Doctors are advised to clean the eartips frequently and to sterilize the diaphragm, the piece which touches the patient.[6].

The single-head stethoscope is the most common type that comes to most people’s minds when they think of a stethoscope. Although it’s the most simple, it does not distinguish sound too well. [10]Electronic stethoscopes, in fact, amplify noise a lot better than a regular stethoscope but they do have some disadvantages. Electronic stethoscope are much more expensive than a regular stethoscope, which works just as efficiently. The price of an electronic stethoscope is somewhere around $175. Another disadvantage would be that other electronics around it could interfere with the noise it is trying to pick up. A cell phone, for example, could cause the electronic stethoscope to pick up other noises. Batteries, as you could guess, are another issue. They run out constantly so doctors always have to be prepared. [8]. The diaphragm of a normal stethoscope will not fit onto an electronic stethoscope, so this stands as very inconvenient. And the diaphragm only comes in one size, instead of coming in a size that works for children also.[9]


A cardiovascular exam using a stethoscope.


  1. 1.0 1.1 1.2 Weinberg, Fred. The History of the Stethoscope US National Library of Medicine National Institutes of Health. Web. Date-of-publication: October 1993.
  2. Bellis, Mary. Stethoscope History Web. Date-of-access: April 24, 2013.
  3. unknown author. History: The Evolution of an Essential Tool 3M Littmann Stethoscopes. Web. Date-of-publication: April 24, 2013.
  4. Layton, Julie. Stethoscope Basics How Stuff Works. Web. Date-of-access: April 24, 2013.
  5. 5.0 5.1 Layton, Julie. Picking Up Sounds How Stuff Works. Web. Date-of-access: April 24, 2013.
  6. 6.0 6.1 Johnson, Steve. Advantages and Disadvantages of a Stethoscope “eHow. Web. Date-of-access: May 7, 2013.
  7. Litherland, Neal. Advantages of a Stethoscope eHow”. Web. Date-of-access: May 7, 2013.
  8. 8.0 8.1 Aguilar, Carlos. Electronic Stethoscopes - Advantages and Disadvantages Ezine Articles. Web. Date-of-access: May 8, 2013.
  9. 9.0 9.1 Keefer, Amber. How Electronic Stethoscopes Work “eHow”. Web. Date-of-access: May 8, 2013.
  10. unknown author. What is an EMT Stethoscope Web. Date-of-access: May 8, 2013.