The Unexpected Sounds of Everyday Objects

The world is a noisy place, filled with sounds that we often overlook. Even the things we consider silent can produce surprising and boisterous noises. It turns out that even the most skilled meditators and ninjas struggle to silence their bodies completely. According to science, our bodies are constantly making a racket, but our brains tune it out, similar to noise-canceling headphones. Neuroscientists have explored this phenomenon in electric fish, which have a unique mechanism to distinguish electrical signals related to their behavior from other inputs.

Ants, known for their chemical signaling, have a hidden talent for chirping. Yes, you read that right—ants chirp! They create sounds by scraping their abdominal appendages against ridges, resembling the action of a spoon on a washboard. Interestingly, worker ants have a different pitch of chirping compared to queens, and their behavior changes when they hear the queen's chirps. Mimicking these sounds and even the scent of queens, some caterpillars and beetles infiltrate ant colonies to reap the benefits of the royal treatment.

Did you ever think that giraffes were silent creatures? Think again! Recent research has debunked the assumption that giraffes make sounds inaudible to humans, similar to the infrasonic secret language of elephants. Giraffes, in fact, produce perfectly audible humming sounds at a frequency of 92 Hertz, but they only vocalize at night. These hums serve as a means of communication and keeping contact in the dark. However, there's an intriguing alternative theory—that the sounds are the result of giraffes snoring or even talking in their sleep.

Contrary to popular belief, fish are not mute creatures. Although they lack vocal cords, thousands of fish species worldwide are capable of producing sounds. Fish create these noises by rubbing or clicking bony structures together or beating their swim bladder like a drum. These sounds play a crucial role in communication, conveying reproductive and territorial information. Interestingly, certain fish species, previously thought to be silent, have been discovered to produce clicks, including the eerie cries of the three-spine toadfish, resembling that of a baby.

Marine worms might not be on your mind when it comes to noisy creatures, but they have one of the loudest sounds among deep-sea dwellers. Bristle worms, also known as polychaetes, usually remain silent, hiding in sea sponge holes when threatened. However, when they encounter danger, they create a bubble by opening their pharyngeal muscles and release the pressure with a shockingly loud "pop" reaching 157 decibels. To put this into perspective, a blue whale's call measures 180 decibels, while the snapping shrimp's snap can break glass at a whopping 189 decibels.

Plants, much to the surprise of many, have their own way of communicating. Scientific research has confirmed that plants emit ultrasonic squeals when they are cut. These sounds, ranging from 20 to 150 kilohertz, lay outside the range of human hearing but can be detected and recorded. Interestingly, even healthy plants occasionally produce these vocalizations. Some studies suggest that plants may possess the ability to perceive sound, as they germinate and grow differently in response to various frequency sounds. However, more research is needed to fully understand the extent of their auditory capabilities.

Even microscopic organisms have a voice, so to speak. Bacteria, despite being billions of times softer than a fist connecting with a punching bag, produce nanoscale beats with their flagella or tails. These beats can be amplified and recorded as sound, potentially aiding scientists in determining bacterial resistance to antibiotics. Similarly, viruses can be compared to sound, albeit in a more fun way. For instance, the DNA sequence of COVID-19 has been translated into music, resulting in compositions ranging from synth-pop to classical tunes.

Cells, the building blocks of life, have their own songs. Sonocytology, the study of cell's nanoscale oscillations, has revealed that different types of cells produce distinct songs that change when they are under stress. This knowledge could potentially be used to detect diseases at an early stage. Researchers have already differentiated between healthy and cancerous prostate cells by analyzing their unique "squeals." However, the sounds of cells are not pleasant melodies; they are more akin to high-pitched screams. Fortunately, these sounds are inaudible to the naked ear and require advanced techniques like atomic force microscopy to capture and study them.

In the vacuum of space, silence is not what it seems. While it is true that sound waves cannot travel through the vacuum, scientists have managed to capture extraterrestrial sounds. These eerie sounds include planetary radio waves converted into audible frequencies, as well as actual sound waves originating from hot gas and plasma surrounding supermassive black holes. Although we currently lack the technology to directly record these sounds, they have been reconstructed and amplified to be audible to our ears. One example is the harrowing baritone of the Perseus black hole, which required a significant increase in frequency to make it audible to humans.

Even silence itself is not devoid of noise. Acoustic chambers, designed to eliminate external noise and capture any internal sounds, are the quietest places on Earth. However, spending time in these chambers can be a disconcerting experience. In the absence of external noise, people start hearing the normally inaudible sounds of their own bodies, such as the hiss of spontaneous firings of the auditory nerve, blood pumping, and the symphony of their digestive system. Prolonged exposure to true silence can also give rise to hallucinations of disembodied noises like swarms of bees or snippets of songs.