Have you ever wondered why joints pop or your nose whistles? Or whether that embarrassing sound was loud enough that others could hear it? (The body’s involuntary noises usually sound much louder to the perpetrator than to bystanders.) You also might wonder if you need to worry about any of this sonic activity.

Common body noises—and how to quiet them…

Flatulence

Passing gas is great fun if you happen to be a 10-year-old boy. It’s not so amusing for the rest of us, particularly when it “slips” at the wrong time—a likely occurrence because the average adult passes gas up to 20 times a day.

What it means: The tight anal muscle that allows us to control what comes out (and when it comes out) also accounts for the sound. The outward rush of air causes the tissues to vibrate. The more air that comes out and the greater the pressure, the louder it’s likely to be.

Gas is partly caused by emissions from intestinal bacteria triggered by certain foods such as beans, broccoli, asparagus and onions. It also may be caused by foods that your body cannot tolerate, such as dairy products or ­gluten. But it’s mainly due to swallowed air. In one study, researchers “tagged” room air with radioactive particles, then looked for the presence of these particles in the intestinal gas of test subjects. They found that most of the expelled gas consisted of the tagged particles.

Helpful: You can control flatulence by reducing the amount of air that you swallow—by  eating more slowly, taking smaller bites and not chewing gum. Also, avoid carbonated beverages. The carbon dioxide gas that gives beer and sodas their “fizz” has to go somewhere—and out it comes.

Over-the-counter products such as Beano can help prevent gas. Take it along with your first bites of gassy foods. Or have a cup of fennel seed tea (available at health-food stores) after a meal for a simple, effective remedy.

Burping

The same air that produces intestinal gas can travel in the other direction and produce a loud belch. It travels upward from the stomach and through the esophagus. The sound that you hear is caused by movements of the upper esophageal sphincter.

What it means: If you don’t burp often and it doesn’t hurt when you burp, don’t give it a second thought. If it bothers you, you can try to swallow less air (see above). You also should curtail your consumption of carbonated beverages.

Peppermint oil (10 to 15 drops in one-quarter cup cold water) is a quick remedy for burping.

Caution: If you burp a lot or the burps cause a burning sensation or a foul taste, you could have gastroesophageal reflux disease (GERD), a potentially dangerous condition in which stomach acids surge upward into the esophagus.

People with GERD tend to have more symptoms in the morning because the body’s secretion of stomach acid is highest at night. They also might have voice hoarseness because the vocal cords are at the same level as the stomach during sleep.

Over-the-counter medications for GERD, such as omeprazole (Prilosec), esomeprazole (Nexium) and TUMS, will help relieve symptoms, but they shouldn’t be used for long periods without checking with your doctor.

Stomach Rumbling

The scientific term for stomach growls, gurgles and rumbles is borborygmus. It tends to get louder when you’re hungry, and it has a disconcerting tendency to occur during silences in conversations.

What it means: The stomach isn’t merely a storage tank. The muscular walls are frequently expanding and contracting. At the same time, the contents of the stomach—mainly food and ­fluids, along with air—do a lot of sloshing. They generate sound waves that are clearly audible.

A stomach growl doesn’t always mean that you’re hungry. It does mean that there’s empty space in the stomach. Just as a half-full bottle makes more noise than a full one when it’s shaken, the stomach is noisier when it doesn’t contain enough food to dampen the sounds.

One way to stop your stomach from gurgling is to have a small banana (which helps absorb stomach acids) and a glass of water. Or try a granola bar, a handful of crackers, some trail mix or a cup of herbal tea.

Joint Pops

It’s normal for joints to snap, crackle and pop, particularly in older adults. The percussive sounds don’t mean that you’re a candidate for surgery. They usually are just a result of pressure, friction and suction.

What it means: The joints that do the most popping—the knees, shoulders, hips and jaw—are ball-and-socket joints. A ball-shape surface at the end of one bone fits snuggly into a hollow depression on the one next to it.

The bone ends are coated with a sheen of a thick, clear liquid called ­synovial fluid. This lubricating fluid on one end clings to the fluid on the next—and makes a distinct snapping sound when you move the joint and the fluids pull apart. “Cracking” the knuckles is a similar phenomenon.

There’s also more “slop” in the joints as you get older. The ends don’t fit together as tightly as they used to. The misalignment can produce snapping or popping sounds. As long as the pops aren’t accompanied by pain, they’re unlikely to be a problem.

Important: If you have noisy joints and other symptoms such as pain and swelling, see your doctor. You could have torn tissues (for example, in the knee), tendon damage or arthritis, all of which can cause popping.

Nose Whistles

When I was a kid, I had bad allergies that caused me to whistle through my nose all the time.

What it means: You have a too-­narrow nasal opening. This usually is due to congestion from allergies and colds.

Simply blowing your nose may eliminate the whistle. If this doesn’t help, try using an over-the-counter saline nasal spray (such as Ocean) twice a day as directed on the label. This nasal moisturizer offers natural, nonmedicating dryness relief, shrinking nasal membranes and thus opening up the “whistling” passage. Nasal decongestant sprays that contain oxymetazoline (such as Afrin) work, but use them only for a day or two—they can cause increased, “rebound” congestion if you use them regularly for more than three days.