For Grown-Ups

Explore how the speed of ‘vibrations’ affects sound. Let your child touch their hand lightly against your throat while you talk. Do they feel anything? All sound is produced by vibration--the rapid shaking of an object, which creates sound waves which travel through the air to our ears. When we speak or sing, vocal chords in our throats (voice boxes) shake, or vibrate, to make the sound of our voices. Let them try to find their own vibration by touching their own neck. When we make a low sound the vibrations move slowly resulting in a ‘low tone’ and when we make a high sound, the vibrations move quickly with a ‘high tone’ as the result.

Find a picture of a violin, viola, cello and string bass. What part of these string instruments vibrates to produce the sound? Making the string vibrate by plucking or bowing makes the sound of string instruments. Rosin is put on the bow hair to make it sticky – when the musician pulls it across a string; it catches and makes the string vibrate. One may also “pluck” the string with their finger, pulling it across the instrument creating a pizzicato.

To make your own instrument for plucking you will need a piece of wood at least 30 cms long and 5 cms wide, a long rubber band, 2 nails and a hammer.

Hammer nails at each end on the same side of the wood. Stretch the rubber band around the nails. Pluck the rubber band and listen to the sound it makes Hold the rubber band down to the wood midway between the two nails and pluck one end of the band. What has happened to the pitch when the rubber band was shortened?
Try changing the width of the elastic band to hear what a thinner or thicker version 
will do!!