Sound Wave & Frequency Simulator
See sound as moving air particles and an oscilloscope trace, change pitch, and hear beats form.
Drag left and right across the waveform to change the pitch, or add a second tone to hear the beats.
About the Sound Wave & Frequency Simulator
Free sound wave & frequency simulator. See sound as moving air particles and an oscilloscope trace, change pitch, and hear beats form. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for physics, the sound wave & frequency simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
See sound as moving air particles and an oscilloscope trace, change pitch, and hear beats form. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Sound Wave & Frequency Simulator
- Use the controls to change Tone 1 frequency, Volume (amplitude), Tone 2 frequency, Medium, Second tone. The simulation reacts instantly.
- Pick an option such as Air 343 m/s, Water 1480 m/s, Helium 965 m/s, Off to switch modes or load an example.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Drag across the scope to sweep the pitch.
- Switch from air to water and watch the wavelength grow.
- Turn on the second tone at 4 Hz apart and read the beat frequency.
- Find the frequency of middle A (440 Hz).
Key ideas you can learn
- Sound is a longitudinal wave: air particles bunch up (compressions) and spread out (rarefactions).
- Higher frequency means higher pitch and a shorter wavelength.
- Wavelength = speed of sound ÷ frequency, so the same note is longer in water than in air.
- Two close frequencies together make beats at the difference frequency.
Where this is used in the real world
Musical instruments, ultrasound scans, sonar, noise cancelling headphones and piano tuning (listening for beats) all use these ideas.
Who is this simulation for?
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is the relationship between frequency and wavelength?
λ = v / f. For a fixed speed, doubling the frequency halves the wavelength.
What are beats?
When two tones of slightly different frequency overlap, the loudness rises and falls at a rate equal to the difference of the frequencies.
Is the Sound Wave & Frequency Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Sound Wave & Frequency Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.