We humans may not have superpowers, but the sensor suite we have is still pretty impressive. We have binocular vision that autofocuses and can detect a single photon, skin studded with sensors for touch, heat, and pain, and a sense of smell that can detect chemicals down to the parts per trillion range. Our sense of hearing is pretty powerful, too, allowing us to not only hear sounds over a 140 dB range, but also to locate its source with a fair degree of precision, thanks to the pair of ears on our heads.
Recreating that binaural audio capture ability is the idea behind this homebrew 3D microphone. Commercially available dummy head microphones are firmly out of the price range of [LeoMakes] and most mortals, so his was built on a budget from a foam mannequin head and precast silicone rubber ears, which you can buy off the shelf, because of course you can.
Attached to the sides of the foam head once it got the [Van Gogh] treatment, the ears funnel sound to tiny electret cartridge microphones. [Leo] learned the hard way that these little capsule mics can’t use the 48-volt phantom power that’s traditionally pumped up the cable to studio microphones; he fixed that problem with a resistor in parallel with the mic leads. A filtering capacitor, an RC network between the cold line and ground on the balanced audio line, and a shield cleverly fashioned from desoldering braid took care of the RF noise problem.
The video after the break shows the build and test results, which are pretty convincing with headphones on. If you want to build your own but need to learn more about balanced audio and phantom power, we’ve got a short primer on the topic that might help.
Continue reading “Homebrew Binaural Microphone Lets You Listen Like A Human”
[Matt] likes to make videos (and he’s pretty good at it judging by the quality of his videos). But video isn’t much without audio. Handheld recorders with small built-in microphones have a fairly high noise floor so [Matt] has a Rode NT1-A — a pricey but very quiet microphone. However, for field work, it isn’t handy since it requires a power supply and preamp to go along with it.
Another problem is that for stereo recording you need two and because they are quiet, they tend to pick up handling noise so you probably need to mount them on tripods. That’s all too much to carry around, especially on a hike. So [Matt] cannibalized two microphones. He repackaged them in a shock mount (made from a bird feeder and elastic), and added a battery pack and a custom preamp. The shock mount eliminates the handling noise and the custom PC boards mean you don’t have to carry a lot of extra gear.
The end result (see the video below) looks like someone made a purse out of a tribble, but it does sound good. If you hang on through most of the video (of fast forward to about 7:25), you can hear the microphones picking up thunderstorms, the ocean, the wind, and even [Matt’s] heartbeat.
Continue reading “Low Noise Floor Microphone”
Binaural audio is probably the coolest thing you can listen to with a pair of headphones. Instead of just a single microphone, binaural recordings use two microphones, set inside an analog for a human head, to replicate exactly what you would hear if you were there.
The only way to record binaural audio is with fake plastic ears attached to a dummy head. Most of the famous microphone manufacturers have something like this, but with a 3D printer, anything is possible. [Carlos] created his own binaural microphone using a 3D printer and went through the trouble of creating a few audio demos. The results are weird, like [Carlos] is whispering into your ear.
The ears used in this microphone setup are taken from a Thingiverse project by [Jonathan March]. This model did not properly model the ear canal,and didn’t have any way to mask the sound from ear to ear; this is why the professional models also include a head. [Carlos] fixed these shortcomings and created a few 3D models that accurately model the human ear and head.
There’s also a simple stereo microphone amplifier for this project that is designed to fit right between the ears. This amplifier was designed in KiCAD, and the PCB is single sided. It’s not quite simple enough to assemble on a piece of stripboard, but [Carlos] did manage to manufacture it on some copper clad board in his mill.
The results? It sounds awesome. [Carlos] put together a demo of his microphone, link below, and it only works if you’re wearing headphones.
Continue reading “3D Printing Binaural Microphones”
Aiming to be the leader in Virtual Reality horror experiences is the immersive VR haunted house in Seattle called ‘The Nightmare Machine’ which promises to be one of the most terrifying events this Halloween. But they need some assistance raising money to achieve the type of scale on a large public level that the project is attempting. The goal is $70,000 within a 30 day period which is quite the challenge, and the team will need to hustle every single day in order to accomplish it.
Yet the focus of the project looks good though, which is to lower the massive barriers of entry in VR that are associated with high hardware costs and provide people with a terrifying 5 minutes of nightmare-inducing experiences. This type of fidelity and range is usually only seen in military research facilities and university labs, like the MxR Lab at USC. And, their custom-built head mounted displays bring out this technology into the reach of the public ready to scare the pants off of anyone willing to put on the VR goggles.
The headsets are completely wireless, multi-player and contain immersive binaural audio inside. A motion sensing system has also been integrated that can track movements of the users within hundreds of square feet. Their platform is a combination of custom in-house and 3rd party hardware along with a slick software framework. The technology looks amazing, and the prizes given out through the Kickstarter are cool too! For example, anyone who puts in $175 or more gets to have their head 3D scanned and inserted into the Nightmare Machine. The rest of the prices include tickets to the October showcase where demos of the VR experience will be shown.
Continue reading “VRcade’s The Nightmare Machine (Kickstarter Campaign)”
A lot of awesome stuff happened up in [Bruce Land]’s lab at Cornell this last semester. Three students – [Pat], [Ed], and [Hanna] put in hours of work to come up with a few algorithms that are able to simulate stereo audio with monophonic sound. It’s enough work for three semesters of [Dr. Land]’s ECE 5030 class, and while it’s impossible to truly appreciate this project with a YouTube video, we’re assuming it’s an awesome piece of work.
The first part of the team’s project was to gather data about how the human ear hears in 3D space. To do this, they mounted microphones in a team member’s ear, sat them down on a rotating stool, and played a series of clicks. Tons of MATLAB later, the team had an average of how their team member’s heads heard sound. Basically, they created an algorithm of how binarual recording works.
To prove their algorithm worked, the team took a piece of music, squashed it down to mono, and played it through an MSP430 microcontroller. With a good pair of headphones, they’re able to virtually place the music in a stereo space.
The video below covers the basics of their build but because of the limitations of [Bruce]’s camera and YouTube you won’t be able to experience the team’s virtual stereo for yourself. You can, however, put on a pair of headphones and listen to this, a good example of what can be done with this sort of setup.
Continue reading “Adding Stereo To Monophonic Audio”
[Matt] wrote in to tell us about this project. He plans on travelling with his MSI Wind and wanted better audio recording capabilities. He decided to install an additional microphone and a preamp. He made a custom preamp and wired it directly to the motherboard. The microphone was then mounted in the laptop screen. The second microphone is placed opposite of the first, about 18cm apart which [Matt] claims gives it a binaural effect. We think that this might just classify as stereo though. Wouldn’t you have to seperate them with a barrier or dampening device for binaural? It doesn’t really matter though, stereo mics are a great addition to the MSI Wind, and he did it very well. He does point out that it picks up a lot of noise though. There’s always room for improvement.
In what some might call a sensationalist article, USA Today reporter [Kim Komando] warns parents of a new danger to their kids: digital drugs. Throughout the article, [Kim] tries to explain how binaural beats (idosers) can effect the brain in many different ways, claiming that some even emulate the effects of illegal drugs. Furthermore, she claims that the “digital drugs” can act as a gateway to trying real drugs. While it seems unapparent to [Kim] that I-Doser has been around for years, it’s not surprising that this article is only being published now. While I understand her argument, parts of it just seem illogical. If anything, wouldn’t binaural sounds provide kids an alternative to illegal drugs? If these sounds really provide the same effects as drugs, wouldn’t they act as a safer option to kids? While this story seems to be one of many sensational stories warning parents to protect their kids, it seems as though parents should really be warned about these sensational stories that are concocted solely to sell newspapers.