I’ve been interested in sound and audio for a long time now. Probably from the time I heard my first beep or click from a child’s toy (can’t be sure), my mind got hooked on these air fluctuations and how to make more of them. Once I got into playing guitar and messing around on computers and patterned air movements (i.e. music), this became a fully-realized obsession. Even with all of the complexity inherent in my musical endeavors, the simple things still feel good, and if I can make a simple Ruby gem that can beep at you, then by Thor’s hammer I will!

Ahem.

Feeping Around

Spending time at the command line, coding away at various things, sometimes I just want to make some noise. Of course, most of us turn to our MP3 collection or Spotify, but that wouldn’t be nerdy enough nor would it involve programming, so I borne feep into the world.

Just to quickly explain the name, a “feep” is an archaic name given to the “soft, electronic ‘bell’ sound” of some old display terminals. I don’t personally remember anyone calling the ding/bing/boop/beep/ping/etc sound of old pre-DOS computers a “feep”, but 1) it’s adorkably fun, and 2) the obvious “beep” is already taken.

Wait, I’ve Heard This One Already

In today’s day and age, the question “Is there something that already exists that does what my application sets out to do?” is almost 100% sure to be answered with “YES, MANY THINGS”. And those many, many things are often open-source and on Github, rife for the rifling through and building from.

Searches across the Internet found several application that make sound, even in Ruby (the language I wanted to make feep in), but nothing I found (at the time) did all of the things I wanted, and that’s when a programmer decides to make their own.

How Make Sound

Name chosen and purpose decided upon, I set out to make a command line tool that could make sound with the following requirements (which increased as I went along):

1) Synthesize a sound from a simple waveform
2) Control the note/frequency, amplitude/volume, and duration
3) Play multiple notes at once in a chord
4) Play multiple notes in a row as a scale

One thing I quickly found was that to make a computer utter a simple “FEEP!” sound via CLI is not exactly intuitive, nor is it consistent across all operating systems. Here are just some of the examples I tried, but there are more:

  • Windows: CTRL-G in a command line prompt to get a ^G system code, then hit enter
    • Not intuitive and more of an unintended beep than anything.
  • Mac/OSX: osascript -e beep
    • A little better, but still a bit wordy and unintuitive.
    • Macs can also use the say "beep" command, but that uses a synth voice and actually says the word “beep” and does not make a beep sound.
  • *nix: echo -e "\a"
    • Basically the same as Mac.
  • Python: python -c "print '\7'"
    • Similar to the Mac way, and just as unintuitive. Why would you think to “print” something when you want to hear something?
  • Ruby: puts 7.chr
    • See the python explanation.

Despite most systems’ insistence on printing sounds, I still felt like Ruby was the best way to approach the issue due to my recent interest in making fun little system applications, so I continued down that path.

My first big break was finding a nice Rubygem library called win32-sound that lets you type something like Sound.beep(100, 1000) and get a tone at 100 Hz for 1000 milliseconds. Now we’re getting somewhere! Alas, it does not work on non-Windows, so I had to dig deeper.

The biggest break came when I stumbled upon a nice person named Joel Strait. He does a lot of open-source applications with audio. The most useful to me were the WavFile Rubygem library and his adaptation of it in NanoSynth. Honestly, it kind of changed my mind about the whole project. I now had a way to solve all the arcane command madness: use WAV files. Instantly cross-platform, consistent in quality, and (eventually) allowing for all kinds of interesting manipulation of the sound itself. Performance-wise and overhead-wise it’s probably not the best, but so far it’s worked fine.

My on-the-fly sound creation engine was ready to be started.

Let There Be Feep

Finding NanoSynth was a boon to productivity, because it gave me a way to make a sound from a specific waveform, at a specific frequency, at a specific volume, for a specific duration. It was just a Ruby script, however, and not a Rubygem, so my initial idea to fork and improve it turned into my own project, which became feep. Once it was gem’d, which was an interesting experience in and of itself, I started to improve it all the ways that my requirements suggested.

NanoSynth created WAV files and, through an optional, additional application (like afplay or sounder.exe), played them, as a completely different step. I wanted to make it all happen in one fellow swoop, without leaving anything behind (by default). So, I have feep auto-play the WAV file (which still requires that additional application) once it’s created, and then delete it, effectively making it a “sound producing” app, not a “sound file creating” app. This all hides the fact that an actual WAV file is being created as neatly as I can manage, since the WavFile Rubygem can’t (yet) play its product without writing to the file system.

After getting the basic functionality working, I later had the idea of being able to play multiple notes in a scale. This was initially a separate gem, pulling in the original feep as a library (wanted to learn how that worked), but it was too much of a hassle and it just got absorbed as a feature. I’m sure there’s a better way to access all possible musical notes besides a static list, but I can’t think of what it would be (if you know, let me know!):

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NOTES = Array[
  'C0','C#0','D0','D#0','E0','F0','F#0','G0','G#0','A0','A#0','B0',
  'C1','C#1','D1','D#1','E1','F1','F#1','G1','G#1','A1','A#1','B1',
  'C2','C#2','D2','D#2','E2','F2','F#2','G2','G#2','A2','A#2','B2',
  'C3','C#3','D3','D#3','E3','F3','F#3','G3','G#3','A3','A#3','B3',
  'C4','C#4','D4','D#4','E4','F4','F#4','G4','G#4','A4','A#4','B4',
  'C5','C#5','D5','D#5','E5','F5','F#5','G5','G#5','A5','A#5','B5',
  'C6','C#6','D6','D#6','E6','F6','F#6','G6','G#6','A6','A#6','B6',
  'C7','C#7','D7','D#7','E7','F7','F#7','G7','G#7','A7','A#7','B7',
  'C8','C#8','D8','D#8','E8','F8','F#8','G8','G#8','A8','A#8','B8',
  'C9','C#9','D9','D#9','E9','F9','F#9','G9','G#9','A9','A#9','B9'
]
NOTES_ALT = Array[
  'C0','Db0','D0','Eb0','E0','F0','Gb0','G0','Ab0','A0','Bb0','B0',
  'C1','Db1','D1','Eb1','E1','F1','Gb1','G1','Ab1','A1','Bb1','B1',
  'C2','Db2','D2','Eb2','E2','F2','Gb2','G2','Ab2','A2','Bb2','B2',
  'C3','Db3','D3','Eb3','E3','F3','Gb3','G3','Ab3','A3','Bb3','B3',
  'C4','Db4','D4','Eb4','E4','F4','Gb4','G4','Ab4','A4','Bb4','B4',
  'C5','Db5','D5','Eb5','E5','F5','Gb5','G5','Ab5','A5','Bb5','B5',
  'C6','Db6','D6','Eb6','E6','F6','Gb6','G6','Ab6','A6','Bb6','B6',
  'C7','Db7','D7','Eb7','E7','F7','Gb7','G7','Ab7','A7','Bb7','B7',
  'C8','Db8','D8','Eb8','E8','F8','Gb8','G8','Ab8','A8','Bb8','B8',
  'C9','Db9','D9','Eb9','E9','F9','Gb9','G9','Ab9','A9','Bb9','B9'
]

Alls Well That Feeps Well

In the end, after a lot of trial and error, and help from the Internet (natch), I got a Rubygem created and added to Rubygems.org! Now, when I want a simple feep sound on my computer, I can go to a command prompt, type feep, and I get a nice sine wave at 440Hz, 1/2 system volume, for 100 ms. If I want something cooler, I type feep -n A#3,B3,D#4,A#4,C#5,A#6 -d 1500 -a 0.25 -w saw for a nice jazzy chord block.

You can just play around with this for fun, or you could essentially use it for any kind of audio-related need you have in your current project, be it an alarm, warning, art installation, or game sound effect.

Also, feel free to fork it and improve it, as I know it’s not as good as it could be (doesn’t even have any tests yet). However, it’s totally useable even now, so go forth and feep, OK?