While the process of understanding and decoding binary code is quite a bit different than Morse Code, the concept of transmitting information in a series of blips and beeps is almost identical to the “on” and “off” bits of computer binary code.
For this reason, the telegraph completely transformed the world of over-the-wire communication, and when radio communication was invented, and particularly during the era of World War II, communicating by transmitting sound in Morse Code was an obvious progression of the technology. The use of Morse Code was so prevalent that guys serving in the military eventually learned to decode Morse by listening to the sound, without the need to reference any decoding codes at all.
Obviously, the world has moved on since then, and we now have email, voicemail, instant messaging systems and cellphones. There seems to be little use in today’s world for the archaic technology represented by Morse Code. However, considering few people today can understand audible Morse Code, and few Internet monitoring or spying apps are set up to intercept sound, Morse Code represents one of the safest methods (short of using encryption) to transmit information to someone. Also – it’s just a really novel thing to play with.
Transmitting & Receiving A Morse Code Message
If you consider the possibilities that Morse Code presents, and if you’re the kind of person that likes novel applications like self-destructing secret messages, then you’ll quickly realize how cool this could be. Here at MUO, we’ve covered a number of ways to send hidden messages, such as Tina’s article on how to encrypt messages but what if you could record an audio file containing an embedded Morse Code message?
If you wanted to further “hide” the message, you could even embed the Morse Code audio as a single track in a multi-track sound file. So long as the recipient knows which track to pull out, and so long as they know the frequency setting of your code (see below), then they can decode the hidden message.
Sounds funky and complicated right? Well it’s not. In this article I’m going to show you how you can use two pieces of software. One is a free Morse Code Generator offered by Robert Ecker. The receiving application that will capture and decode the audio is called CwGet.
First, let’s set up and record a MIDI file containing your Morse Code audio.
Robert Ecker’s online Morse Code generator lets you type in any text message, and it outputs everything shown above – the dots and dashes, the sounds verbally written in text, a Play button where you can hear the Morse Code, and of course a button to save the audio to file.
Before you type your text, adjust the parameters at the bottom of the page to make the sounds stretch out a little longer so that it’s easier for the receiving software to analyze and decode the Morse.
The only things I changed were the dot and dash settings, just about doubling them. For my tests, I simply left this window open, and then analyzed the sound using the receiver software reading the sound directly from my laptop microphone. However, if you save the audio file, you will send the file via email (or embed the track into another audio “cover” file) and email it. The person receiving your audio will play the file out loud while running the receiver software.
So let’s take a look at how you can receive and analyze the Morse Code message. As a side note – the message I typed above and converted to Morse Code was: “This is so cool”.
Using CwGet To Decode Morse Code Audio
CwGet is pretty impressive. It can accept any audio from the PC microphone, and it will convert it into text using Morse Code. If you leave the software running in a loud room, it’ll spit out a lot of garbage, so it’s important to configure the software to only decode the sound level of your Morse Code audio, and ignore the random noise in the room.
When you first run the software, it’ll look similar to this except that you’ll see two red lines bouncing along the bottom of the sound wave in the bottom panel. This is the software constantly analyzing sound spikes to determine which peaks to use as the Morse Code source. It will work like this, but not well. Instead, you want to set the peak level manually.
First, go into Setup and click the box to “enable manual auto-threshold limit.”
Now, play your Morse Code audio file, and you can click within the lower pane to set where the threshold limit should be where the software attempts to decode the Morse Code.
Try to click at the level that is right at the center of the peak and valley of each “beep” of your morse code. Here, I’ve clicked to set the lower red line (manual threshold) right at the center of those beeps. The upper red line is the software trying to automatically identify the peak itself. Once you set your manual threshold, you’ll notice that as you replay the Morse Code audio, the software will accurately decode the text message out of the audio file.
A few tips that greatly enhances the software’s ability to decode the message:
- Turn up the computer audio as loud as possible so that the microphone gets a very clear reading (or directly connect your audio output to your microphone input).
- Make sure the beeps and blips of the Morse Code audio file are long enough so the receiving software has time to recognize the transition.
- If using your speaker and microphone, try to do the decoding in a very quiet room with little background noise.
Once you see this setup in action, I’m sure your imagination will take off. You’ve probably heard of encrypting messages in image files, well now you can encrypt messages in random sound files that, to any random listener, will sound like white noise. Or transmit codes to your friends over Skype if you need to send something sensitive and you’re concerned about someone intercepting the message text.
Or…you can just have a little bit of fun transforming text messages into sound, and then back again. That’s how I spent my Saturday morning, and I had a lot of fun doing it – I’m sure you will too! Try it out and let me know in the comments section what you think of the setup.