Why Do Farts Make Noise?

Did you just fart a little bit ago? Were you wondering why it made such a ruckus? Well, let’s take a deep dive look into exactly what makes a fart make noise and some of the other interesting fart factors as well.

Answer:

The noise from farts come mostly from the tightness of the muscles around the anal canal. If the muscles are tight, the sphincter will vibrate anywhere from 5 to 25 times per second. This is the main factor behind the sound of a fart. Some others factors are diet, clothing, hair, and physiology.

So, let’s get down into the nitty gritty folks. In order to understand why a fart makes the noise it does, we first have to understand exactly what a fart truly is. Farts are the colloquial term used to describe flatulence. Farts are always funny, so let’s just make that clear and get it out of the way as soon as possible. They are a natural part of life, unless you are Chelsea (the owner of Chelsidermy). In which case, you don’t fart and you never have before in your life. Not only this, but you likely never will.

We are going to look at the science behind a fart and why it even happens in the first place in order to get to the final answer that we are looking for. What makes the noise happen in your fart?

What Causes Farts?

What causes flatulence? The normal digestion in your body includes the breakdown of the food that you eat within your stomach and intestines. During this process, bacteria and enzymes eat this food and release different gasses as a product. Usually this gas that is released by the bacteria and enzymes is made up of nitrogen, hydrogen, carbon dioxide, and methane. Sometimes there is some sulfurous gas in these byproducts as well. After this gas is released by the enzymes and bacteria it then makes its way through the rest of the intestines and digestive tract in order to be expelled through your rectum and anus.

The average fart contains a general percentage of gasses as follows:

Nitrogen 20% to 90%
Carbon Dioxide 10% to 30%
Hydrogen 0% to 50%
Methane 0% to 10%
Oxygen 0% to 10%
Sulfur usually is in trace negligible amounts.

While these factors can range widely and vary, not only per person, but per day due to the different diets and physiology; but they can also change due to many other environmental factors as well.

While these gasses are what largely makes up each fart, they are not the main source of the smell from a fart. This is attributed to the Volatile organic compounds (VOCs) that are also released as a result of flatulence. These are chemicals that, at room temperature, have a high vapor pressure. This is a fancy way of saying that they dissipate into the air easily in a normal setting. These VOCs are the main driving factor behind the odors that you get a waft of after a big fart. They are also a direct result of the same bacteria that eat on the food within your body.

The volatile organic compounds consist of 3 main aspects, and they each play their own role in your farts.

The VOCs include the following:

Indole – This is an aromatic organic compound, so the structure is made with the inclusion of a benzene ring. It is the result of the breakdown of an amino acid called Tryptophan. This organic compound does have a specific odor that strongly resembles rotten eggs and is a major reason as to why some farts smell like that.

Skatole – This organic compound is the product of the amino acid Methionine being broken down. This one has a strong fecal smell as well and is mainly the culprit behind the barnyard smelling farts. It is the chemical structure of skatole and indole that make them smell to our noses. They are cyclic compounds which have a loan pair of electrons on the Nitrogen atoms. This is a fancy way of saying that they easily bond with other particles and atoms with hydrogen bonds and then are easily released into the air for us to smell. (Poop particles)

Fatty Acids – These compounds are the major cause of the farts that smell more like soured milk, and they are the result of the fermentation process of undigested food in your G.I. tract. If the bacteria are unable to digest these foods fully, and they instead ferment in this way, they will be expelled with a strong odor.

So Why Do They Make Noise?

Fart noises are the result of your anal sphincter vibrating and releasing the gas from inside of your body. While it is extraordinarily challenging to offer an exact rate of sphincter vibration during a fart, it can be said that the usual range is somewhere around 5 to 20 Hz. It is important to note that this is merely an estimation based on observations in experiments and unreliable data.

Each person has a different range of fart sounds that can be produced as the major factors of the resulting sound are shape of the anal canal as well as the tension of the muscles around the anus and sphincter. The sound is also, clearly, influenced by the sheer volume and velocity of the gas release as well. This means, that if your capacity is higher, you may be able to fart longer and louder than someone with a lower capacity.

Taking into consideration the information that an average fart ranges between 5 and 20 cycles per second, we can see where a great deal of the noise actually stems from.

This is not to say that the gas escaping, and the sphincter vibrations are the only factors that play a role in a fart making noise. The butt cheeks also offer their own role in affecting this whole process. As we briefly mentioned earlier, the tight or loose muscles around the anal canal can play a pivotal roll in the fart noise. These sounds are surely influenced by the butt cheeks due to the mass or lack-there-of as well as any clenching of the cheeks that may be had. All of these variables play their own part in you having a tight sphincter or a loose sphincter. This will directly influence the farting process and the structure of the anal canal all together.

If you clench your butt cheeks, you may experience a squeaking high-pitched fart. This is due to the diameter of the anus being squeezed shut and reducing the size of the hole that the gas has to escape from. Think of a water hose, and how the water comes out faster and harder when you put your thumb over most of the open end. If you want to be quiet, this is not the way to go. If you want to be particularly noisy, this may be your funny little ticket. Fart loud, fart often.

If, however, you are bent over and your sphincter is relaxed and stretched open; the fart may even be silent and make no noise audible by the human ear. This is because, what causes the majority of the loud fart noise is the tight sphincter muscles, and you have removed this from the equation.

The sound of your farts depends on so much. The gas released from the inside of your body isn’t as simple as you may have previously thought it was. If this comes as a surprise to you, you are not alone.

We are not done blowing your mind, however, because there is one more fantastic piece of information about your butt cheeks. The butt cheeks themselves can actually act much like a resonating chamber and can amplify the sound of your fart as well as shape it into something different than it would have been without their influence. They can change both the frequency and the tone of the sound itself that escapes you body.

Not only can the butt cheeks themselves have such a massive effect on the sound of your farts, but the hair and… debris… around the anus can also have a particularly impactful role as well.

So, all in all, the main aspect of your farts sound comes from the actual sphincter itself, and the fact that it vibrates upon releasing the gas from inside of your body. However, your but cheeks, muscle tension, age, physical fitness, diet, hair composition, and any foreign debris plays a role as well. This means that nearly every fart is unique in its own special way like a snowflake.

Why are some farts good smelling?

That is because everyone like their own brand.

Outside Factors:

Diet:

Some foods have an affect on your flatulence at a considerable rate. You may have heard before that eating beans, broccoli, or dairy can actually increase your gas. This is true, and with an influx of these foods can be correlated with an influx in farting as well. The more gas you have in your body, the louder and more frequent your farts will be. This is to say that your farts will happen more often and be louder if you eat foods like these that increase the gas produced by your G.I. tract.

Here is a list of some of the foods known to give you the most farts and the loudest farts:

Lentils
Chickpeas
Kidney Beans
Broccoli
Cauliflower
Cabbage
Onions
Garlic
Milk
Cheese
Ice Cream
Fruits with skins and seeds
Whole Grain
Sparkling Water
Soda Pop
Artificial Sweeteners
Fried Food
Fatty Meat
Peppers and Hot Sauce

Digestive Disorders:

There are medical conditions that you may have that can increase both the frequency and velocity of your farts. Irritable Bowel Syndrome (IBS) as well as Inflammatory Bowel Disease (IBD) absolutely cause an increase in gas production and thus increase the amount and noise of your farts.

Celiac disease is another one, and it is actually classified as an auto immune disorder that has symptoms directly correlated to the ingestion of gluten. The consumption of gluten in a person with celiac disease causes the lining of the small intestine to become damaged. This can cause bloating and an increase in gas.

Small intestinal bacterial overgrowth (SIBO) is just as it sounds in the name. This is an overgrowth of bacteria in the small intestine and it can lead to symptoms that often include abdominal pain, bloating, and increased gas.

Gastroparesis is another one, but this one is a little bit different than the others. This illness causes the stomach to take too long in its process of emptying the food into the small intestine. This often results in vomiting, nausea, and increased gas as well. This one is a bit more serious than some of the others.

Clothing:

If you are wearing tight clothing, this can further constrict your butt cheeks and thus help you in producing a louder and higher pitched fart. On there other hand, if you are wearing heavier or looser clothing, it can actually muffle the sound and help to dampen the noise made by your fart. If you are in a lucky position, with loose heavy clothing, and your butt cheeks are relaxed, you may not even make any noise when your let one rip.

The tight clothing can also compress your abdomen, which will of course make it harder for you to keep one in during your efforts to hide it on a first date or while you are in church.

Recap & Summary:

Well, you know what caused you to go searching for this, but now you also have the answer to your question. So, if anyone ever asks you, or brings this up in passing, you will have a detailed and well-informed answer to provide them on why their farts make noise and why they smell too. Who knew it was such an in-depth topic, and would warrant so much research and analysis? I absolutely loved writing this article, it was hilarious.

If you enjoyed this article and learning about this topic, there are many others just like it right here in our Information and Learning categories.

Thank you so much for taking the time out of your day to read this article!

Why Do Farts Make Noise? - The Science Behind Flatulence

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