The vibrating ruler pushes the molecules in the air, making them bunch together. As the ruler vibrates back and forth it makes waves of molecules pushed together (pressure waves). The molecules transmit these pressure waves through the air into our ear, where they are converted to electrical signals that get sent to our brain.
When the ruler is longer it vibrates more slowly, so pushes molecules together less often, so the waves of molecules are further apart – the frequency of sound waves are lower. Lower frequency waves have a lower pitch.
When the ruler is shorter it vibrates more quickly, so makes higher frequency pressure waves, which have a higher pitch.




(video – varying width & thickness)


(video – varying length)



Deriving the concept of how different lengths and thickness of material can produce sounds in different notes, I picked soft wood as my main material.

The point of using only 1 material, is to highlight on how simply by varying the certain conditions of the same material, it can produce sounds of different notes and layers! 🙂

Another material used is the marble. It is interesting as it creates a special sound together with the soft wood. 



An enveloped structure (similar to 20 sided dice/ virus cell wall)
Ms Cheryl’s chicken feeding toy
Chinese yo-yo

Egg Shaker



Creating unique pieces in varying sizes (length & thickness) and then assembling each of them together. They must be closely pieced so that the marble would not fall out! yell


Finally trimming pieces and adding the marble in, before sealing the piece. Would be horrible news if I forgot to put the marble and sealed it first… 

The original idea ended here, but EUREKA. The sound invoked an idea – chinese yoyo!


The sticks and strings were then added to include entertainment value to the piece.


TADA my finishing piece! 


Please visit my PDF for more!
[Applications & creative process]


  1. As mentioned in class, some suggestions for further exploration & experimentation: several layers to ‘shell’ to create a more complex labyrinth for the marble to roll around. Maybe the inner most shell could be wood then metal then plastic or glass to add more sound textures. Also try a slightly more elastic material as rope? It is an interesting toy concept!  At first glance I thought of the Reverse Bungee G-max at Clarke Quay. Aha! Idea for application? 🙂

  2. If you really only want to stick to 1 material, you could also play with wood of different densities. That could create a range of sounds from more solid sounds to hollow sounds.. Balsa is very light & brittle so the sound would definitely be more hollow than say bakau or pine or even plywood. With this in mind, you could even customize the layers of shells made from different wood which can be added on to the core or removed.

  3. Just reviewed your pdf. What are your 3 KEY words driving your design?  Don’t you think it would be more helpful having a photo montage of your intended applications than just text? Just imagine you want to market your design… How best would you present it?

Leave a Reply