What are ultrasonics? (2025 Update)
Educational and Fun Activities
Written by Alexandra Stone
10 July 2024
🕓 10 min
What Are Ultrasonics?
When we think of sound, we usually imagine what we can hear. But did you know there are sounds beyond human hearing? These high-frequency sound waves, called ultrasonics, play a crucial role in science, medicine, and nature.
At The Science of Sound, we love making complex science fun and engaging. Through our STEM workshops, after-school clubs, and holiday camps, children explore the fascinating world of sound waves, frequency, and technology in a hands-on way.
In this blog, we’ll dive into: ✔ The science behind ultrasonics ✔ How animals use ultrasonics ✔ Everyday applications of ultrasonics ✔ A fun experiment to explore sound waves
By the end, you’ll discover how these hidden sound waves shape the world around us!
1. The Science of Ultrasonics
Ultrasonics refers to sound waves with frequencies higher than 20,000 Hz, which is beyond the range of human hearing. While humans can typically hear sounds between 20 Hz and 20,000 Hz, ultrasonics can be detected by certain animals and used in various technological applications.
Ultrasonic waves have shorter wavelengths than audible sound, making them ideal for precise detection and imaging. They travel through air, liquids, and solids, and their ability to bounce off objects makes them useful in navigation and diagnostics.
How Ultrasonics Work:
✔ Higher frequency = shorter wavelength, allowing for detailed detection.
✔ Used in medicine, engineering, and industry for imaging and object detection.
✔ Animals like bats and dolphins rely on ultrasonics for echolocation.
Fun Fact:
Some high-frequency ultrasonic waves can generate heat, which is why they are used in medical treatments and industrial cleaning.
2. The Importance of Ultrasonics
Many animals rely on ultrasonics to communicate, hunt, and navigate their environments. Unlike humans, these animals can detect and produce high-frequency sounds, giving them an evolutionary advantage in the wild.
Animals That Use Ultrasonics:
✔ Bats – Use echolocation by emitting ultrasonic clicks that bounce off objects, helping them navigate in complete darkness.
✔ Dolphins & Whales – Send out ultrasonic pulses underwater to detect prey, obstacles, and even communicate with each other.
✔ Dogs & Cats – Can hear ultrasonic frequencies, which is why special silent whistles work for them but not for humans.
✔ Moths & Insects – Some species have evolved to detect bat echolocation and escape before being caught.
Fun Fact:
Some fish, like the toadfish, produce ultrasonic calls to communicate, especially during mating season!
To learn more about sound frequencies and their impact, check out our post What is Audio Frequency?.
3. Can Humans Use Ultrasonics?
Ultrasonics plays a critical role in modern technology, medicine, and engineering. These high-frequency sound waves are used in imaging, cleaning, and security systems, making them essential in daily life.
Where Ultrasonics is Used:
✔ Medical Imaging (Ultrasound) – Doctors use ultrasonic waves to see inside the body, especially during pregnancy and for organ diagnostics.
✔ Industrial Testing – Ultrasonic scans help detect cracks in bridges, airplanes, and pipelines, preventing potential disasters.
✔ Cleaning Technology – Ultrasonic cleaners remove dirt from delicate objects like jewelry and electronic parts without harsh scrubbing.
✔ Security & Motion Sensors – Ultrasonic waves detect movement in alarm systems, providing enhanced security for homes and businesses.
✔ Pest Control – Some devices emit ultrasonic waves to repel rodents and insects without using chemicals.
Fun Fact:
Many electric toothbrushes use ultrasonics to break down plaque more effectively than regular brushing!
4. Fun Activities with Sound
Although humans can’t hear ultrasonic waves, we can demonstrate how they work using simple materials. This experiment helps children understand how sound waves travel through materials and bounce off objects.
Materials Needed:
✔ A metal spoon
✔ A string (about 1 meter long)
✔ Your ears!
Steps:
- Tie the spoon to the middle of the string.
- Hold one end of the string against each ear.
- Gently tap the spoon against a table and listen.
- You should hear a clear, bell-like sound, which travels through the string directly to your ears!
Why This Works:
✔ The sound waves travel through the string instead of the air, similar to how ultrasonics work in water and solid objects.
✔ This mimics how ultrasonic imaging creates clear internal images in medical scans.
Find more activities like this in our blog Crafting Musical Instruments with Everyday Materials to inspire your child's love for science and sound.
Final Thoughts
Ultrasonics might be beyond human hearing, but their impact is everywhere, from animal communication to medical breakthroughs. By understanding ultrasonics, we can appreciate the hidden world of sound beyond our ears!
Key Takeaways:
✔ Ultrasonics = sound waves above 20,000 Hz, used for navigation, imaging, and detection.
✔ Animals like bats and dolphins rely on echolocation to find food and navigate.
✔ Ultrasonic technology is used in medical imaging, industrial testing, and security systems.
✔ Humans have adapted ultrasonics for non-invasive medical scans and even pest control!
At The Science of Sound, we bring sound science to life through STEM workshops, after-school clubs, and holiday camps, making learning about ultrasonics interactive and fun!
