Disclaimer: I claim no ownership to the contents and media of this article. Text and images belong to Nintendo Co., Ltd.; the original article can be read here: 学研さんと「HD振動」のヒミツについて調べてみました。
Did you know the Nintendo Switch has a feature called HD Rumble that’ll let you enjoy games even more? Have a look at this movie of “Count Balls”, one of the games included in the title “1-2-Switch”.
When you tilt the JoyCon, it’ll feel like there are marbles rolling around and bumping into each other inside it. The sensation your hand will feel is almost real. (To put it in more scholarly terms, that sensation is called “tactile feedback”.)
The HD Rumble feature is what makes this kind of tactile feedback possible. What does the mechanism generating those vibrations looks like?
Enlisting the help of a certain published academic, we did some research! We conducted some tests fit for a summer break research project (translator’s note: Japanese kids do research project assignments during their summer breaks), and got to the bottom of the HD Rumble’s secrets.
What are vibrations to begin with?
What comes to your mind when you think about the word “vibration”? It’s a broad term encompassing anything from quakes to some more interesting effects.
To investigate that, we’ll do an experiment with a “paper cup telephone”.
Experiment #1: Making a paper cup telephone
A paper cup telephone is a pair of paper cups connected by a length of string. We made a video that shows how to make one. (If you plan to make one yourself, please read these safety notes (note from translator: there’s a link to a list of safety notes) so you won’t hurt yourself, and do it with an adult present.)
The picture shows how to use the phone. One person puts a paper cup to their ear, the other person talks directly into the second paper cup. The string has to be pulled taut for this to work.
The voice of the person talking is transmitted to the cup of the person listening!
Experiment #2: Observing the string closely
How does the voice travel from one paper cup to the other? What’s the secret of the string connecting the cups? To examine the mechanism, we will observe the string more closely.
Do you see how the string moves in sync with the voice? What we see here is that the voice directed into the paper cup telephone is turned into vibrations and transmitted to the listener.
By the way, if you replace the parts of the phone with different materials, you can achieve interesting effects. Try switching out the paper cups for tin cans, the string for a length of fishing line, for example.
The transmission of vibrations
Experiments #1 and #2 tell us that a voice can be transmitted by vibrations. It seems like vibrations have the ability to transmit information. Maybe the ability of the JoyCon to make us feel rolling marbles is related to that. To find out, we will check if we can produce tactile feedback with our phone as well.
Experiment #3: Creating the sensation of rolling marbles using a tin can phone
This time we will use a phone made of tin cans and fishing line. These materials conduct vibrations even better. (We explain how to make a phone like that at the end of the article.)
When you run this experiment, you can feel the bouncing and rolling marbles and beads!
Experiment #4: Observing the line
We will now observe what goes on with the line more closely, just like in experiment #2 when we transmitted voice.
This experiment proves that not only voice, but also tactile feedback can be transmitted by vibrations. What’s more, we can tell the difference between marbles, beads, and other objects by how they feel. The slight differences in vibration make the hand feel distinctly different sensations, like “plonk” or “rumble” or “clink”. Small differences in vibration create different kinds of tactile feedback.
The experiments taught us that the source of the tactile feedback of the tin can phone is the minute vibrations transmitted by the string.
The JoyCon doesn’t have a string, but inside it is a mechanism creating minute vibrations in much the same way. (That mechanism is called a linear vibration motor.)
Systems like the Wii U also have a vibration feature, but they can’t produce the very minute vibrations that we know are necessary from our experiments. With the Nintendo Switch’s linear vibration motors and their ability to create very delicatly varying vibrations, it is possible to create the sensations of rolling marbles, water sloshing around in a glass and more.
Games to experiment with
Now we all understand the way the HD Rumble works a little better. Do some experiments this summer break with some of the games that use it!
(The article lists 1-2-Switch, Mario Kart 8 Deluxe, ARMS, Splatoon 2 and THUMPER as some of the games available for the Switch)
Translator’s note: At the foot of the article are instructions on how to make a tin can phone. I left those out since I thought they aren’t relevant/easy to look up. If there’s demand I’ll be happy to translate them as well 😉