Sound and Volume - Presentation

The concept of sound and volume is a fundamental topic in physics, particularly when discussing the nature of sound. Volume, in this context, refers to the loudness of a sound, which is quantified in units called decibels, symbolised as dB. Students will explore the direct relationship between the energy used to produce a sound and its resulting loudness; the greater the energy, the louder the sound. An example provided is the use of jack hammers in road maintenance, which can operate at a volume ranging from 63 dB to a considerable 94 dB. This high volume of sound, due to intense vibrations, has the potential to cause hearing damage, thus emphasising the importance of wearing ear defenders to protect one's hearing.

Further investigations into sound involve practical experiments to understand how the volume of sound changes with varying energy levels, such as the difference in loudness when an object is dropped from different heights. Students learn that the material of the object also influences the loudness of the impact. Additionally, the size of the outer part of the ear, which collects sound vibrations, is discussed with reference to how larger ears may collect more vibrations, potentially leading to a louder perception of sound. This is illustrated with historical devices used to detect distant enemy planes by capturing sound vibrations. The lesson also covers how to determine the effectiveness of ear defenders, with the best ones reducing the volume of sound as measured by a sound meter. By the end of the lesson, students should be able to articulate what volume is, the unit it's measured in, and the correlation between the energy exerted to create a sound and its loudness.