Adding stereo to monophonic audio

board

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.

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Stereo microphones in an MSI Wind

binaurial

[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.

Parents beware of “digital drugs”


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.

[via Woot]

[photo: BrittneyBush]