Sound - Changing Pitch

Objectives

To understand which vibrations cause different pitches in sounds.

To create instruments that make different pitches.

Resources

Lined paper | Variety of instruments | Different thickness of rubber bands

Today's Lesson

Main Activity

Watch the videos about the pitch and loudness of sound.

Discuss with your child how to distinguish between pitch and volume.

Access the information about pitch and volume on the STEM Learning website below to develop your child’s understanding of altering the pitch of different instruments.

EXPLORE - What factors affect the pitch and the volume of sound? (STEM Learning)

If you have access to a guitar, or have ever handled one, discuss with your child how the thicker strings create the lower pitched sounds. Note also that the length of a guitar string can be changed by pressing it down onto a ‘fret’ on the neck of the guitar.

The nearer the fret is to the main body of the guitar, the shorter the string is. This creates a faster vibration (a shorter wavelength) and therefore a higher pitch. The slower the vibration (a longer wavelength), the lower the pitch.

You can recreate a guitar if you don’t have one by putting elastic bands over a box with a hole cut into it - see picture above. Help your child to make some notes on what they have discovered through their investigation on the Internet.

Extend the lesson by looking visually at how sound waves are represented (see below). The lower the pitch of a sound, the less frequent the sound waves occur. The higher the pitch, the more frequent the sound waves occur.

[W15] Image2.gif

Resources

Citations

[1] www.youtube-nocookie.com [2] www.stem.org.uk [3] player.vimeo.com