Phasing, Secrets, and Modern Music

Image from Lynda.com YouTube video about audio recording tutorial

Sending coded messages takes many forms.  What about sound? Can a person encrypt a message in audio that cannot be deciphered? The answer is yes! In this unit we look at how sound waves can to hide  information to send a coded message.  We examine these same principles and how they can be destructive or creative in sound recording. We also look at the technologies created from Homer Dudley’s research.

Goal

  • Convey knowledge and understanding of sound wave phase concepts in recording, modern music, and encryption.

Sound Phasing Encoding and Decoding in History

Sound Phasing Terms and Concepts

  • Wave Crest
  • Wave Trough
  • Wave Cycle
  • 180 degrees out of phase
  • Phase cancellation
  • In Phase
  • Acoustic Phase Cancellation
  • Electronic Phase Cancellation
  • 3 to 1 rule
  • Sound canceled out
  • White Noise
  • Pink Noise
  • Brown Noise
  • More to come…

Encoding and Decoding Explained

Product

  • Create a blog post with embedded media from SoundCloud, YouTube, and Flickr of an in and out of phase sound file, encoded and decode sound file, a karoake file, and an auto-tuned file. Include notes, definitions, and explanations and key terms, concepts and processes.

Examples

  • Coming soon…

Steps

  • Day 1 – Create Blog Post, Add Section Headings, Listen to Podcast and Take Notes
    • Create blog post titled, Phasing, Secrets, and Modern Music
    • Copy and paste the headings below
      • Summary
      • Sound Phasing Encoding and Decoding in History
      • Sound Phasing Terms and Concepts
      • Sound Waves – In and Out of Phase
      • Encoding and Decoding with Sound Waves
      • Auto-Tune Track
      • Karaoke Track
      • What I Learned and Problems I Solved
    • Under the Sound Phase Encoding and Decoding in History heading:
  • Day 2 – Phasing Sound Terms and Concepts
  • Day 3 – Create Two Sound Tracks: One in Phase and One Out of Phase
    • Review terms from yesterday
    • Record an audio track in Audacity
    • Duplicate the region of audio so that it plays twice in the track
    • Duplicate the track
    • Invert the second region of the duplicated track
    • Play the tracks
    • Listen for the difference in the regions
    • Export as a mp3, upload to SoundCloud, and embed under the Sound Waves – In and Out of Phase heading
    • Explain what you learned under the What I Learned and Problems I Solved heading
  • Day 4 – Create Two Tracks: One with Voice and One as an Encryption Key ‘Noise’ Track
    • Track 1: Record a voice track in Audacity
    • Track 1: Duplicate the voice region of audio so that there are three instances of it on this track
    • Track 2: Record a second track of noise, generated by Audacity or another source,  underneath the second region of the voice track
    • Track 2: Copy and paste the noise region under the third region of voice
    • Track 3: Copy and paste the noise region from track 2 under the third voice region
    • Track 3: Invert the noise region
    • Play the tracks
      • Listen for the difference in the regions
      • You should hear the voice region, then the noise encrypted voice region, then finally the decoded noise and voice region
    • Export as a mp3, upload to SoundCloud, and embed under the Encoding and Decoding with Sound Waves heading
    • Explain what you learned under the What I Learned and Problems I Solved heading
  • Day 5 – Create an auto-tuned track
    • Import a vocal track with two regions (one will be auto-tuned, one will not) into Audacity
    • Download and install the Free AutoTune for Audacity (GSnap) plugin
    • Read the auto-tune tutorial: wikihow.com/Manually-Auto-Tune-With-Audacity
    • Auto-tune the second region of the track
    • Export a mp3, upload to SoundCloud, and embed under the Auto-Tune Track heading
    • Explain what you learned under the What I Learned and Problems I Solved heading
  • Day 6 – Create a Karaoke Track
    • Import a song with two regions (one will become karaoke, one will not) into Audacity
    • Watch tutorial: Create Karaoke Tracks by Removing the Vocals in Audacity
    • Perform the karaoke process the second region of the track
    • Export a mp3, upload to SoundCloud, and embed under the Karaoke Track heading
    • Explain what you learned under the What I Learned and Problems I Solved heading
  • Day 7 – Finish Work and Publish Blog Post
    • Under the What I Learned and Problems I Solved heading
      • Explain what you learned and at least one problem you overcame
      • Include a link to a tutorial you used and
      • Describe how you used it
    • Under the Summary heading
      • Write a brief description overview of the whole project
  • Day 8
    • Present sound files

Tools

  • Audacity
  • Soundcloud
  • YouTube
  • Flickr

Resources

Feedback Form

  • Phasing, Secrets, and Modern Music Project Feedback Form (PDF) – COMING SOON!