Light-to-Sound


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Look at any tree in any breezy day. You see its branches gently moving with the wind, the top swaying this way and that. Now imagine that you can somehow record the movement of the tree, speed it up, and play it back as sound, as if it was the movement of a guitar string. How would it sound?

To answer this really pressing quesiton I set up on a quest - to capture the movement of the tree, convert it to sound, and play it back. And why stop at trees? How about listening to the movement of a hanging bird feeder, the flickering of a candle, or the sound that a nervous guy pacing this way and that across a room would make if speeded up couple of hundred times?

On this page you can see the result of several of those experiments. If you want more technical information about the light-to-sound convertor, check the Details page.

Sample Recordings

Here are some of the recordings I took with the device. Please, note that the frequency range is quite high, so computer speakers may have hard time reproducing the sounds accurately. For this reason I recommend using headphones when listening to these recordings - this way you won't be missing 90% of the sounds.

	Hanging bird feeder. The "boing-boing" noise is caused when birds are landing or taking off the feeder, making it swing. You can also notice differences in the main oscillation frequency, depending on whether there is a bird in the feeder or not. The bird extra weight reduces the swinging frequency.
	Candle in a dark room. The flickering of the flame makes for interesting tweeting noices.
	Another candle in a dark room.
	Vertical window blinds moved by the draft through an open window. The "underwater" quality of the sound probably comes from the natural resonance frequency of the blinds. In addition, as they swing from side to side, the individual blades of the blinds interact with one another.
	Branch of a sycamore tree. Probably it is not surprising that it sounds like wind blowing through a tree - it's the same phenomenon, just on different scales. What you normally hear when walking under a tree on a windy day is the sum of all small vibrations of leaves and minor branches. The swinging of the a big branch and the tree as a whole evidently mirrors the same process, just at longer timescales.
	Swinging palm about 100 yards from our house. The recording is taken over the full course of the day - when the evening sets in you can hear the palm gradually becoming invisible and correspondingly the volume gradually decreasing.
	Here the sensor is pointed toward my hands as I play several different pieces on the piano. The audio clip is quite short and is repeated two times to save you pressing the "Play" button.
	Light reflected off me, nervously pacing across the room for 30 minutes or so, thinking about something. The light sensor was left uncapped (no telescope or any other optics) and just pointed in my general direction.

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Overview	Details	Other Projects