An Introduction to Sound - Teacher Explanation

Welcome to Lesson 4.13, 'An Introduction to Sound', part of the Year 4 Unit on Sound. This lesson offers a variety of cross-curricular opportunities, including Design and Technology (DT), where pupils will create a stringed instrument, and Maths, through the use of bar charts and graphs to represent experimental results. Historical research is also encouraged, with pupils exploring ancient musical instruments. In this lesson, pupils will explore how sounds are made, specifically through vibrations, and will be introduced to safety measures when using rubber bands and tuning forks to prevent minor injuries. The practical activities involve flicking rulers and using tuning forks correctly, striking them on the heel rather than hard surfaces to avoid damage.

During the lesson, students will engage in an activity called 'twanging', using rulers to investigate the relationship between an object's length and the 'squeakiness' of the sound it produces. This experiment demonstrates that shorter objects vibrate more quickly, which results in a higher frequency and a higher-pitched sound. Additionally, pupils will delve into the world of tuning forks, learning how to read the inscriptions on them that indicate musical notes and frequencies measured in Hertz. They will also construct their own musical instruments using pencils, elastic bands, and a cereal box, experimenting with the effects of changing the effective length of the elastic band on the sound produced. This hands-on experience reinforces the concept that the frequency of vibration is related to the length of the vibrating object and, consequently, the quality of the sound it generates.