Spoiler Warning: Shinsou Hitoshi

So as the kick starter for this blog I'll be discussing a character of the popular anime and manga My Hero Academia. Shinsou Hitoshi, a character who breaks the fundamental rules of heroes that have been ingrained in our heads since the first action hero comic. More specifically, I’ll be exploring the support item he gains later in the series.

Shinsou Hitoshi first shows up during the intro to the sports festival arc. Right away he makes an impression on us. Even as a student from general studies, he's unafraid to stand up to the students from 1-A, specifically the resident hot-head Bakugou. He doesn't even hesitate to call out his attitude and the blank way he insults him seems more like he's stating a fact rather than picking a fight. Sooner than later we get introduced to his quirk. It’s explained as a somewhat villainous quirk called Brainwashing, a power that allows Shinsou to “Make anyone who answers him do his bidding” (Chapter 33 Horikoshi). Right away the series throws our ‘hero bias’ back in our faces. Most people think of superspeed or flight when it comes to a power for a superhero. Even the way the quirk is explained to us, pushes this view of a non-heroic quirk. Words like “bidding” don’t exactly make him seem friendly.

The series explores this though. Shinsou explains how he was more or less bullied for the villainous nature of his quirk. People tried to push him into the role of the villain because of something he couldn’t control--which, even though this is just a story in an anime, is a very deep and very real topic. If you think about it, Shinsou’s quirk would be extremely effective against villains and could potentially solve conflicts without fighting.

The quirk only has two real drawbacks. The first is a seemingly random detail; his quirk doesn't work over phones or through speakers of any kind. The second is the fact that someone has to verbally respond to him for his quirk to take effect. This means if his quirk is known, it’s fairly easy to come up with countermeasures. Just not talking would be an example of one.

Here’s where one of his support items comes in. The item itself is an interesting looking mask made of several panels and dials (as seen below). He calls the item “artificial vocal cords” and it does exactly what it sounds like. By moving the dial, Shinsou can make his voice mimic another person’s, making it easier to trick people into responding to him.

Simple enough, right? Wrong!

Remember that odd detail about how his quirk doesn’t work when converted into electrical signals? That same detail means that if the device was purely an electronic voice changer, his quirk would lose effect. This means that each of the panels is strategically placed there for the soundwaves to bounce between and that the dial either tilts or just moves the panels in general. But how does this work specifically and what is it made out of?

First let's dive into what sound is exactly.

Sound is a type of energy created when things vibrate. If that seems a little far fetched try humming but place your hand on your vocal chords. Can you feel the vibrations? Another example is hitting a drum, making the top of the drum move at a high speed you most likely can’t see. As the sound travels through the air it bounces off the particles, making them vibrate, until it reaches your ears. Then your brain does its thing so we can actually process it as noise or speech. This also means that the more particles there are for the sound to bounce off of, the faster the sound moves. These particles vibrating through the air are called longitudinal waves (or longitudinal sound waves in this case). Every time the sound wave bounces off something, it loses a bit of energy (that’s absorbed by the “something”) until there isn’t anything left to lose. With that in mind let's get into Shinsou’s voice changer.

The device is clearly built to make the sound bounce around in different ways before the vibrations escape the mask. The jagged surface of the mask actually helps that, assuming it’s the same way inside the mask as it is on the outside. The reason for this is something called “Diffraction”. This is how sound travels around a corner. As the wave hits a jagged surface or corner, it splits into two lesser waves moving in opposite directions.

The way Shinsou’s mask would work is that, as the wave bounces, it would do one of two things. Either it would hit another corner and diffract into multiple waves that interfere with each other or it would hit the flat surface of a panel. This would cause the wave to “refract”, changing the speed and wavelength, as well as bending the wave. As stated by the EarMaster Textbook “the shorter the wavelength, the higher the frequency, and the higher the pitch” (Chapter 3.1). Therefore by changing the wavelength, you can either raise or lower the pitch. Once it leaves the mask it’s created a different sound, or the sound of someone else's voice. This all happens in the split second between when Shinsou would speak and when someone else would hear him. The dial on the corner would change the angles of the panel and also the angle the sound waves would bounce, making different sounds. The only part we can’t explain is how it combats the sound being quieter when the process is done.

To answer what the mask is made of, it could be any dense material that doesn’t absorb much energy. Having any material less absorbing is ideal so his voice wouldn’t come out muffled or too quiet. Also, the denser the material, the more particles it has and the easier it is for the vibrations to travel through it. With that in mind there are many materials that the mask could be made of, though the most likely option is some type of light steel. Steel’s density can range anywhere from 7.75 to 8.05 g/cm3 and it’s very versatile. It has many types of alloys each with different strengths and weaknesses making it a perfect choice for the mask.

It’s apparent that despite everything, the mask would be very complicated to use. The hours Shinsou must have put into mastering it, let alone using it quickly, must have been numerous. It all goes to show just how determined he is to be a hero in this future society ruled by quirks.

The last question you might have is: Is this possible to make in real life? The answer is a definite, sorta. While following some rules, the mask ultimately ignores others. In real life it would be nearly impossible to copy a specific person's voice without extensive research at the very least. It also conveniently forgets that his voice would be quieter, meaning Shinsou would have to get closer to his opponent to use it. That doesn’t mean it’s not fun to play around with the concept though!

That’s all I got for this week. Don’t forget to comment and suggest any ideas for theories you want me to explore if one comes to mind!

Sources:

Cavallo, Christian. “Steel vs. Titanium - Strength, Properties, and Uses.” Thomasnet® - Product Sourcing and Supplier Discovery Platform - Find North American Manufacturers, Suppliers and Industrial Companies, Thomas, www.thomasnet.com/articles/metals-metal-products/steel-vs-titanium-strength-properties-and-uses/#:~:text=To%20speak%20generally%2C%20steel%20is,both%20heat%20and%20electricity%20readily.

“EarMaster - Music Theory & Ear Training on PC, Mac, IPad and IPhone.” 3.1 Acoustics for Music Theory, www.earmaster.com/music-theory-online/ch03/chapter-3-1.html.

Elert, Glenn. “Density of Steel.” Density of Steel - The Physics Factbook, hypertextbook.com/facts/2004/KarenSutherland.shtml.

Reflection of Sound, www.nde-ed.org/EducationResources/HighSchool/Sound/reflection.htm.

Refraction of Sound, Advanced Technological Education, www.nde-ed.org/EducationResources/HighSchool/Sound/refraction.htm.

“Sound - The Science of Waves, How They Travel, How We Use Them.” Explain That Stuff, 21 May 2020, www.explainthatstuff.com/sound.html.