Science Buddies: "Ask an Expert"

So for my science project I decided to do the "hacking the air-gap" project and if you refer to table 1 you see ultrasonic sound (my project topic) is measured in db but the online tone generator is in Hertz. How can I convert them.

My project is going to be "Can we receive info from an air gapped computer?" (not the actual project title). I'm trying to make each key to be a different amount of Hertz have my dad type a random phrase/sentence measure the sound and then translate it. The problem is I have to measures of units I don't know how to convert and I don't know what ultrasonic sound would be in Hertz.
Thanks.


[Admin note - project url: https://www.sciencebuddies.org/science- ... er-hacking ]

Hi Anonjoe,

The online tone generator emits a sound wave with a specified frequency. “Hertz” is the unit for frequency. The unit for the amount of sound (or sound level) is the decibel or db. The entry in table 1 that you asked about is referring to the level of sound not the frequency.

For the experiment you've described you'll need to measure the frequency (Hertz) of the sounds emitted by the different keys. There are frequency analysis apps available that can make this measurement.

I hope this helps. Please post again if you have more questions.

A. Norman

Thanks for your reply,
I have one more question.
How would I assignment different sounds (using the online tone generator) to different keys (I will be using word in my project) is there macros or a program? This part of coding is out of my feild of knowledge.
Thanks again!

Hi Anonjoe,

Sorry, but coding is outside of my expertise. You may get a better answer if you post on the Math and Computer Science forum.

Your computer has sound hardware that can be accessed via program commands. Once you've identified the commands for this in the programming language you're using, you could write a program that accepts keyboard input and assigns a tone to each character entered. And there may be several other methods for accomplishing this.

I hope this helps. Please post again if you have more questions.

A. Norman

HI Anonjoe,
You can use program such as Soundplant to assign a sound to a specific key.
Here's a link for a tutorial for how to do so:
https://www.cnet.com/pictures/launch-so ... -photos/2/

Good Luck and please post again if you have any other questions!
Willey

Thanks!

Hi Anonjoe,

LeungWilley and norman40 have already provided some good information. I wanted to add a couple things:

We have a bunch of projects that use an app called Google Science Journal. It is capable of measuring sound in both dB and Hz, so may be worth looking into: https://www.sciencebuddies.org/science-journal-app

Also, be careful if you plan on doing the project specifically with ultrasonic sound. By definition, ultrasonic sound is out of the range of human hearing (which typically goes from about 20 Hz up to 20,000 Hz - so ultrasonic sounds are higher than 20,000 Hz). Most computer/phone audio equipment - for example your computer's speakers and your phone's microphone - is designed to work in the human hearing range, and might not be able to produce or record sounds at ultrasonic frequencies. In other words, just because you type 100,000 Hz into an online tone generator, doesn't mean your computer speakers will actually be able to play a tone at 100,000 Hz. Or even if they can, if you are using Science Journal, there's no guarantee your phone will be able to detect the high-frequency sound. So if you try this, I would start at lower frequencies (in the human hearing range) and then work your way up to see if it still works with ultrasonic.

(LeungWilley and normal40 - please chime and and correct me if I'm wrong about this - for example, some quick Googling of speaker frequency response typically shows a big dropoff around 20kHz: https://www.google.com/search?q=speaker ... 80&bih=947)