No Installation Needed! ‘CR-WEB’ (Narika) — The Perfect Tool for Sound Experiments, Even on School PCs
Don’t you find that sound unpleasant? Experience the mystery of “beats” with this free smartphone app!
Imagine an orchestra before a concert or a band during practice. You hear various instruments playing their own notes, and it can sound like a chaotic cacophony, right? Well, hidden within that sound is a fascinating scientific phenomenon.
This time, I’d like to introduce a magical web app that lets you easily experience this “mystery of sound” on your smartphone or tablet. It’s the “Low-Frequency Oscillator App CR-WEB,” available on the Narika website!
https://www.rika.com/web-app/cr-web-detail
What are “beats”? The collision of sound waves
What’s great about this app is that you can freely produce sounds of different pitches (frequencies) from the left and right speakers. The buttons are also designed to be large, making it easy to operate on a tablet.
For example, let’s try playing a “1000 Hz” sound from the left and a “1001 Hz” sound from the right, just slightly different. What do you hear? Doesn’t the sound seem to get louder and softer periodically, making a “womp, womp…” sound?
This is a phenomenon in physics called beats.
Sound has the properties of a wave. When two waves with slightly different frequencies overlap, the parts where the peaks and peaks meet reinforce each other (the sound gets louder), and the parts where the peaks and troughs meet cancel each other out (the sound gets softer). This wave interference is what we perceive as the periodic change in the loudness of the sound, or beats.
These beats are actually super useful for tuning musical instruments. You play the instrument you want to tune at the same time as a reference sound (like a tuning fork) and listen for the moment the beats disappear. When the beats vanish, it’s proof that the two frequencies are perfectly matched. It’s a fantastic example of using the science of sound with our own ears.
What’s your ear age? Try the audible range check!
Another fun use for this app is checking your own audible range. Generally, the human ear can hear sounds in a range from a low of 20 Hz to a high of 20,000 Hz.
However, we tend to lose the ability to hear high-frequency sounds as we age. The “mosquito tone,” which is said to be audible only to young people, uses this very principle.
Be sure to use this app to gradually increase the frequency and see how high a pitch you can hear. You can even try it with family and friends. You might be surprised by the results!
From Classroom Lessons to Personal Exploration
Since “CR-WEB” runs on a web browser, there’s no need to install a specific app. The biggest advantage is that it can be used on devices with usage restrictions, such as Chromebooks often distributed in schools. This makes it an incredibly powerful tool for teaching the properties of sound in physics experiments.
It’s a wonderful app that allows us to perceive the invisible existence of “sound” with our ears and with scientific knowledge. I encourage everyone to explore the mysterious world of sound!
