A mysterious sound coming from a mysterious source

The Mysterious Sounds Only Kids Can Hear

Have you ever heard a sound that someone else couldn’t? Maybe it was a high-pitched ringing or a soft buzz. For most adults, these sounds are imperceptible, but for children, they may be all too common. In fact, there are entire ranges of sound frequencies that are only audible to young ears. But what are these sounds, and why can’t adults hear them? Let’s delve into the science behind high-frequency sounds and explore the mysterious world of the sounds only kids can hear.

The Science Behind High-Frequency Sounds

In order to understand why kids can hear sounds that adults can’t, we must first understand how sound waves work. Sound is created when something vibrates, such as a guitar string or a human vocal cord. These vibrations create pressure waves in the air, which our ears detect as sound. The frequency of these waves determines the pitch of the sound, with low frequencies producing deep sounds and high frequencies producing high-pitched sounds.

How the Human Ear Perceives Sound

The human ear is an incredible structure that is specifically designed to detect and interpret sound waves. When a sound enters the ear, it first passes through the outer ear and into the ear canal. From there, it vibrates the eardrum, setting three tiny bones in motion. These bones amplify the sound and transmit it to the inner ear, where it is transformed into electrical signals that are sent to the brain.

The inner ear is made up of two main parts: the cochlea and the vestibular system. The cochlea is responsible for converting sound waves into electrical signals that can be sent to the brain, while the vestibular system is responsible for maintaining balance and spatial orientation.

Age-Related Hearing Loss and Frequency Range

As we age, our ability to hear high-frequency sounds diminishes. This is due to a natural process called presbycusis, which affects most people to some degree. Presbycusis is caused by the gradual deterioration of the hair cells in the inner ear, which are responsible for detecting high-frequency sounds. This means that while young children may be able to hear sounds with a frequency of up to 20,000 hertz, most adults can only hear up to 16,000 hertz.

However, it’s important to note that not all hearing loss is age-related. Exposure to loud noises, certain medications, and other factors can also contribute to hearing loss at any age.

The Role of Hair Cells in Hearing

One key factor in our ability to hear certain sounds is the presence of tiny hair cells in our inner ear. These cells are responsible for converting the mechanical vibrations produced by sound waves into electrical signals that can be transmitted to the brain.

There are two types of hair cells in the inner ear: inner hair cells and outer hair cells. Inner hair cells are responsible for detecting sound waves and transmitting them to the brain, while outer hair cells act as amplifiers, increasing the sensitivity of the inner hair cells and improving our ability to hear soft sounds.

Unfortunately, hair cells can become damaged over time, reducing our ability to hear certain frequencies. This is why hearing loss is often associated with aging, as the hair cells in the inner ear gradually deteriorate over time.

However, researchers are currently exploring ways to regenerate hair cells in the inner ear, which could potentially lead to new treatments for hearing loss in the future.

The Mosquito Tone: A Sound Designed for Young Ears

One sound that has gained notoriety in recent years is the “mosquito tone.” This sound, which has a frequency of around 17,000 hertz, was originally designed as a way to deter loitering teenagers. The idea was that by playing the tone at a high volume, shop owners could drive away young people without disturbing other customers. The theory was that since most adults can’t hear the sound, it would be a harmless way to keep unwanted visitors away.

The Invention and Purpose of the Mosquito Tone

The mosquito tone was invented in the early 2000s by a Welsh security company called Compound Security Systems. The company marketed the tone as a safe and effective way to deter teenagers, particularly in areas with high levels of vandalism and crime.

Compound Security Systems was founded in 1986 by a group of former police officers who saw a need for better security systems in the private sector. Over the years, the company has developed a range of innovative security solutions, including the mosquito tone.

The idea for the mosquito tone came about when the company’s founder, Howard Stapleton, was shopping with his son. He noticed a group of teenagers loitering outside the store, and he became frustrated that there was no way to drive them away without disturbing other customers. That’s when he came up with the idea for the mosquito tone.

Applications and Controversies Surrounding the Mosquito Tone

In the years since its invention, the mosquito tone has been used in a variety of ways beyond its original purpose. Some schoolteachers have used the tone as a way to keep students focused, while others have used it to prevent cheating on exams. However, there has also been controversy surrounding the use of the mosquito tone, particularly with regards to its potential impact on children’s hearing.

Some studies have suggested that exposure to high-frequency sounds like the mosquito tone can cause hearing damage, particularly in children and teenagers. This has led to calls for the tone to be banned or regulated more heavily.

Despite these concerns, the mosquito tone remains a popular tool for deterring unwanted visitors. In addition to its use in shops and schools, the tone has also been used to prevent loitering in public spaces like parks and bus stations.

Real-World Examples of the Mosquito Tone in Action

One real-world example of the mosquito tone in action was its use during the 2008 Beijing Olympics. Organizers used the tone to deter loitering and vandalism near Olympic venues, particularly in the lead-up to the games. The tactic was deemed successful, with many vandals staying away from the area.

Another example of the mosquito tone in action is its use in the United Kingdom to prevent teenagers from congregating outside of shops and other businesses. Many businesses in the UK have installed the tone outside of their premises, and some local governments have even used the tone to disperse groups of young people in public spaces.

Despite its controversial nature, the mosquito tone remains a popular tool for deterring unwanted visitors, and it is likely to continue to be used in a variety of settings for years to come.

Other Sounds Only Kids Can Hear

While the mosquito tone may be the most well-known example of a sound only audible to young ears, there are many other high-frequency sounds that kids can hear. Some of these include ultrasonic pest repellents and electronic devices that emit high-pitched sounds, such as certain types of computer monitors and televisions. There are also a variety of animal sounds that humans can’t hear, including the ultrasonic calls of bats and rodents.

Ultrasonic Pest Repellents and Their Effects on Children

Ultrasonic pest repellents are devices that emit high-frequency sounds designed to repel pests such as rodents and insects. These devices work by emitting a sound that is unpleasant to the pests, causing them to leave the area. While these devices can be effective, there are concerns about their impact on children’s hearing.

Some studies have suggested that exposure to high-frequency sounds can cause hearing damage, particularly in young children. The American Academy of Pediatrics recommends that children under the age of 12 should not be exposed to ultrasonic pest repellents, as their hearing is still developing and may be more susceptible to damage.

Electronic Devices Emitting High-Frequency Sounds

Many electronic devices emit high-frequency sounds that are imperceptible to most adults. This can include certain types of televisions, computer monitors, and other electronics. While the sounds themselves are harmless, some people may be sensitive to them, experiencing headaches or other symptoms when exposed to them for prolonged periods of time.

It’s important to note that not all high-frequency sounds are harmful. In fact, some electronic devices use high-frequency sounds to improve their performance. For example, some types of ultrasonic sensors are used in cars to help with parking and collision avoidance.

Animal Sounds Beyond Adult Hearing Range

Many animals, particularly rodents and bats, emit ultrasonic calls that are beyond the range of human hearing. These sounds serve a variety of purposes, including communication, navigation, and hunting. While we can’t hear these sounds directly, they can be detected with specialized equipment, such as ultrasonic microphones.

Scientists have been studying these ultrasonic calls for years, and have discovered some fascinating things about the behavior and communication of animals. For example, bats use ultrasonic calls to navigate and hunt, and can even use them to detect the size and shape of objects in their environment.

Overall, while high-frequency sounds may be imperceptible to most adults, they can have a significant impact on the world around us. Whether it’s repelling pests, improving electronic performance, or unlocking the secrets of animal behavior, these sounds play an important role in our lives.

The Impact of High-Frequency Sounds on Children’s Health

While many of the sounds only audible to kids are harmless, there is growing concern about the potential impact they may have on children’s health. This includes both physical damage to the ear and potential psychological effects.

Potential Hearing Damage from Prolonged Exposure

Exposure to high-frequency sounds over long periods of time can cause hearing damage, particularly in children whose ears are still developing. This can lead to both temporary and permanent hearing loss, making it important to protect young ears from excessive noise exposure.

Psychological Effects of Inaudible Sounds

While we may not consciously perceive high-frequency sounds, they can still have an impact on our psychological state. Some studies have suggested that exposure to these sounds can cause feelings of anxiety, irritation, and even aggression. This is particularly true for the mosquito tone, which has been criticized for its potential impact on children’s mental health.

Strategies for Protecting Children’s Hearing

To protect children’s hearing from high-frequency sounds, it’s important to limit their exposure to loud noises wherever possible. This can include turning down the volume on electronic devices, avoiding areas with loud background noise, and wearing ear protection in noisy environments. By taking these simple steps, we can help ensure that young ears stay healthy and free from damage.


In conclusion, the mysterious sounds only kids can hear are a fascinating facet of the science of sound. While many of these sounds are harmless, there is growing concern about their potential impact on children’s health and well-being. By understanding the science behind high-frequency sounds and taking steps to protect young ears from excessive noise exposure, we can help ensure that the next generation grows up with healthy hearing that will last a lifetime.