human

10 Articles

Binaural Microphone On A Budget

May 10, 2026 by 26 Comments

For as many speakers as someone can cram into a surround sound system, humans still (generally) only have two ears to listen to those sounds with. This means that, for recording purposes, it’s possible to create incredibly vivid three-dimensional sounds with just two microphones, provided that there’s an actual physical replica of a human ear attached to each microphone. This helps ensure that all the qualities of the sounds are preserved in a way a real human would experience them, and as [David Green] demonstrates, these systems don’t need to be very expensive.

This build doesn’t just use models of human ears for recording sounds through. The silicone ears are mounted on a styrofoam mannequin head as well, which provides some sound isolation between the two microphones, much like a real human head. The ears are mounted in appropriate locations with the microphones installed inside, and the entire microphone apparatus is positioned on a PVC rig with a camera so that binaural audio will be recorded for anything [David] points it at.

Although he had some issues interfacing two microphones using 19th-century technology instead of soldering everything together, the build still eventually came together, and only for around $70 USD. However, this build is a bit dated now, so prices may have changed by now. It’s still a great way to produce realistic stereo sound without breaking the bank, but it’s not the only way of getting this job done.

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Hackaday Links: August 3, 2025

August 3, 2025 by 17 Comments

When all else fails, there’s amateur radio — and handwritten notes. Both ham radio and clear thinking helped rescue a mother and her son from a recent California camping trip gone wrong. While driving to the campsite in the Stanislaus National forest, the 49-year-old mother had the not-uncommon experience of GPS leading her and her 9-year-old son on a merry chase, sending her down a series of forest roads. Eventually the foliage got too dense for the GPS signals to penetrate, leaving the pair stranded in the forest with no guidance on how to get out.

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Hackaday Links: March 24, 2024

March 24, 2024 by 6 Comments

Way to rub it in, guys. As it turns out, due to family and work obligations we won’t be able to see the next Great American Eclipse, at least not from anywhere near the path of totality, when it sweeps from Mexico into Canada on April 8. And that’s too bad, because compared to the eclipse back in 2017, “Eclipse 2: Solar Boogaloo” is occurring during a much more active phase in the solar cycle, with the potential for some pretty exciting viewing. The sun regularly belches out gigatons of plasma during coronal mass ejections (CMEs), most of which we can’t see with the naked eye because not only is staring at the sun not a great idea, but most of that activity occurs across the disk of the sun, obscuring the view in the background light. But during the eclipse, we — oops, you — might just get lucky enough to have a solar prominence erupt along the limb of the sun that will be visible during totality. The sun has been quite active lately, as reflected by the relatively high sunspot number, so even though it’s an outside chance, it’s certainly more likely than it was in 2017. Good luck out there.  Continue reading “Hackaday Links: March 24, 2024” →

Ask Hackaday: What’s The Deal With Humanoid Robots?

July 31, 2023 by 44 Comments

When the term ‘robot’ gets tossed around, our minds usually race to the image of a humanoid machine. These robots are a fixture in pop culture, and often held up as some sort of ideal form.

Yet, one might ask, why the fixation? While we are naturally obsessed with recreating robots in our own image, are these bipedal machines the perfect solution we imagine them to be?

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Never Stare Down A Robot

May 13, 2023 by 18 Comments

There are a few things historically difficult to make a robot do. Stairs, of course, are the obvious problem. But realistic blinking behavior is harder than you might think. At first, it might seem frivolous and simple to have a robot blink, but according to Italian scientists, it is both more important and more difficult than you probably think.

Blinking is a nonverbal cue when humans communicate. The post quotes a Finnish researcher:

While it is often assumed that blinking is just a reflexive physiological function associated with protective functions and ocular lubrication, it also serves an important role in reciprocal interaction.

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Decellularization: Apples To Earlobes

April 30, 2018 by 40 Comments

Our bodies are not like LEGO blocks or computers because we cannot swap out our parts in the living room while watching television. Organ transplants and cosmetic surgery are currently our options for upgrades, repairs, and augments, but post-transplant therapy can be a lifelong commitment because of rejection. Elective surgery costs more than a NIB Millenium Falcon LEGO set. Laboratories have been improving the processes and associated treatments for decades but experimental labs and even home laboratories are getting in on the action as some creative minds take the stage. These folks aren’t performing surgeries, but they are expanding what is possible to for people to do and learn without a medical license.

One promising gateway to human building blocks is the decellularization and recellularization of organic material. Commercial scaffolds exist but they are expensive, so the average tinkerer isn’t going to be buying a few to play with over a holiday weekend.

Let’s explore what all this means. When something is decellularized, it means that the cells are removed, but the structure holding the cells in place remains. Recellularizing is the process where new cells are grown in that area. Decellularizing is like stripping a Hilton hotel down to the girders. The remaining structures are the ECM or the Extra Cellular Matrix, usually referred to as scaffolding. The structure has a shape but no functionality, like a stripped hotel. The scaffolding can be repopulated with new cells in the same way that our gutted hotel can be rebuilt as a factory, office building, or a hospital.

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Mechanisms: The Lever, It’s Everywhere

April 26, 2018 by 28 Comments

Levers are literally all around us. You body uses them to move, pick up a pen to sign your name and you’ll use mechanical advantage to make that ballpoint roll, and that can of soda doesn’t open without a cleverly designed lever.

I got onto this topic quite by accident. I was making an ornithopter and it was having trouble lifting its wings. For the uninitiated, ornithopters are machines which fly by flapping their wings. The problem was that the lever arm was too short. To be honest, as I worked I wasn’t even thinking in terms of levers, and only realized that there was one after I’d fine-tuned its length by trial and error. After that, the presence of a lever was embarrassingly obvious.

I can probably be excused for not seeing a lever right away because it wasn’t the type we most often experience. There are different classes of levers and it’s safe to say that most people aren’t even aware of this. Let’s take a closer look at these super useful, and sometimes hidden mechanisms known as levers.

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