https://github.com/trishume/screentunes

Play tones through an LCD monitor from a web page using an electronics quirk in some displays.
https://github.com/trishume/screentunes

Last synced: 3 months ago
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Play tones through an LCD monitor from a web page using an electronics quirk in some displays.

• Host: GitHub
• URL: https://github.com/trishume/screentunes
• Owner: trishume
• Created: 2015-01-08T23:01:46.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2024-01-12T16:45:11.000Z (about 1 year ago)
• Last Synced: 2024-10-16T18:54:32.270Z (3 months ago)
• Language: JavaScript
• Homepage: http://thume.ca/screentunes
• Size: 229 KB
• Stars: 137
• Watchers: 8
• Forks: 16
• Open Issues: 3
• Metadata Files:
  • Readme: Readme.md

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• awesome-starred - trishume/screentunes - Play tones through an LCD monitor from a web page using an electronics quirk in some displays. (others)

README

        
# Screen Tunes

It turns out that some LCD monitors will emit a tone when patterns of repeating bars are displayed on the screen.

This pattern varies based on the size of the bars. The goal of this project is to eventually be able to play some

music through the screen using a web page.

I found out about this effect from the Hacker News comments on a page that was about a completely different bar spacing effect

but produced sound out of some monitors (including my external Samsung LCD).

[Some commenters](https://news.ycombinator.com/item?id=8856930) produced theories including that this is caused by

the expansion and contraction of capacitors/inductors in the display as the screen scans down and the black pixels take a different

amount of power than the white pixels. This theory suggests that varying the width of the bars would change the pitch,

which indeed does happen.

This is mainly intended as an experiment out of curiosity and geekery; it has no practical use.

## Technique

I simply created a full screen canvas where I draw an animated and variably spaced sequence of black and white bars.

Displaying this pattern in a large browser window on some LCD monitors produces a tone.

## Plans

#### Music

Theoretically this could be used to play simple digital chiptune-like songs. By animating to different bar widths the notes

could be changed at around 60HZ. It might even be possible to play multiple notes at once by either partitioning the screen

vertically into different chunks with different bar widths on each, or perhaps just alternating bar widths at 60HZ might be too

fast for the ear to discern the alternation.

#### Calibration

Using the web audio API I could direct users to put a microphone near their screen and do a bar width sweep and record the

frequency and relative amplitude. This could used for both data collection on this phenomenon and to calibrate the playing of

music to emit the correct pitch at the correct amplitude.