What is audio amplitude? (2025 Update)
Educational and Fun Activities
Written by Alexandra Stone
26 July 2024
🕓 10 min
What Is Audio Amplitude?
Sound is all around us, from the quietest whispers to the loudest fireworks. But what determines how loud or soft a sound is? The answer lies in audio amplitude—a key factor in how we experience sound waves.
At The Science of Sound, we explore how sound waves work through hands-on learning in our STEM workshops, after-school clubs, and holiday camps. Understanding amplitude helps children grasp the science of volume, energy, and sound vibrations in a fun and interactive way.
In this blog, we’ll break down:
- The science behind amplitude
- How amplitude affects hearing
- A fun experiment to explore amplitude at home
By the end, you’ll understand why amplitude is essential in shaping the sounds we hear every day!
1. The Science of Amplitude
Amplitude refers to the size or height of a sound wave, which determines how loud or soft a sound is. The greater the amplitude, the louder the sound; the smaller the amplitude, the quieter the sound.
When looking at a sound wave on a graph, amplitude is represented by the height of the wave from its resting position to its peak.
This is measured in decibels (dB), with higher decibels indicating louder sounds. For example:
✔ Whisper = ~30 dB
✔ Normal conversation = ~60 dB
✔ Rock concert = ~120 dB
Why Amplitude Matters:
Amplitude affects how we experience sound in daily life—whether we’re listening to music, talking, or hearing a siren in traffic.
Fun Fact:
Did you know that a jet engine can reach over 140 dB, which is loud enough to cause pain?
If your child is interested in sound waves, you can explore more about how they work in our blog post How Sound Waves Can Be Fun for Primary School Children, where we share hands-on experiments for kids to understand sound.
2. How Amplitude Affects Our Hearing
Our ears are highly sensitive to amplitude, allowing us to perceive sounds at different volumes. But exposure to high-amplitude sounds for too long can cause damage, making it essential to protect our hearing.
Understanding Amplitude and Hearing:
✔ Low amplitude = Soft sounds (e.g., whispering, rustling leaves).
✔ Medium amplitude = Normal conversation, background music.
✔ High amplitude = Loud music, alarms, fireworks.
How Loud is Too Loud?
Sounds above 85 dB (e.g., traffic, concerts) can cause gradual hearing loss over time. Sounds above 120 dB can cause immediate damage to the eardrum.
Fun Fact:
The human pain threshold is around 130 dB—which is why standing near a jet engine or fireworks can be physically painful!
Check out The Amazing World of Sound: Discover the Secrets of How We Hear! to better understand how the human ear processes different sounds.
3. Experiencing Amplitude at Home
You don’t need fancy equipment to explore amplitude—just a speaker and a few simple materials! This fun experiment helps children visualize how amplitude affects sound vibrations.
Materials Needed:
✔ A speaker or any sound-playing device
✔ A bowl covered with plastic wrap
✔ Uncooked rice or salt
Steps:
- Stretch plastic wrap tightly over a bowl.
- Sprinkle a small amount of rice or salt onto the surface.
- Play music at a low volume and observe how the rice barely moves.
- Gradually increase the volume (amplitude) and watch how the vibrations increase, making the rice jump!
Why This Works:
Louder sounds (higher amplitude) generate stronger vibrations, making it easier to see sound waves in action!
Want to make this experiment even more fun? Combine it with our 5 Child-Friendly Ways to Visualise Sound at Home for more engaging sound exploration activities.
Final Thoughts
Audio amplitude plays a major role in how we experience sound, from quiet whispers to thunderous booms. Understanding amplitude helps us better appreciate sound waves and take steps to protect our hearing.
Key Takeaways:
✔ Amplitude = volume – Higher amplitude = louder sound, lower amplitude = softer sound.
✔ Measured in decibels (dB) – Sounds above 85 dB can damage hearing over time.
✔ Hands-on learning makes it fun – Simple experiments help children see and feel amplitude in action.
By engaging in interactive STEM activities, children develop a deeper appreciation for the science of sound.
At The Science of Sound, we bring concepts like amplitude, frequency, and vibration to life through our STEM workshops, after-school clubs, and holiday camps!
