SCIENCE FOR GRADE 1-8 Understanding Sound
This is a schematic of our ear, can you spot the eardrum? It gets moved by sound pressure waves that come from a recorder, a clapper , drum or any sound producing source: car horn, our voice …
From the eardrum some bony levers pass the movement on to the inner ear where it is processded to tickle the nerves in our cochlear and then our brain makes sense of all this. Enjoy the music!
When you blow into the flute the air is directed through the wind way (B) which is the space between the body of the flute and the block (A). We used a cork that was cut away on one side as the block. We pushed it into the plastic pipe and presto, you made a WIND WAY!
The air stream then hits the LIP (C), it is the sharp edge cut into the pipe. The location of the wind way and the lip are important!
When the air stream hits the lip it gets split and little whirls of air pass over the lip to the outside of the flute and to the inside, one whirl out and then one whirl in, and then all over again, in a very rapid motion. This makes the air inside the flute VIBRATE. The vibrations in the body of the flute behind the lip cause PRESSURE CHANGES in the air inside the flute. And, those pressure changes or vibrating air you pick up with your ear, and now you hear sound in the form of a TONE.
With our flute you can make the VOLUME of air inside the flute larger or smaller by pulling the plunger out or pushing it in. Smaller air volume give a higher PITCHED sound, more air in the inside flute, when you pull the plunger out will give a lower pitch.
Now, build your flute and experiment. It will drive everybody “crazy” but it is great fun!