Representing sound
Lesson details
Learning outcome
I can describe how computers represent sound.
Key learning points
- Sound is a pressure wave that causes the air to vibrate.
- A sound sample is a measure of a sound wave at a point in time.
- Samples of sound are digitised using a specified resolution so they can be processed by a computer.
- Sample rate is a measure of the number of samples taken each second.
Keywords
Sample - the measurement of a sound wave at a point in time
Digitisation - converting data to a binary sequence
Resolution - the number of bits used to represent a sample
Sample rate - the number of samples captured per second
Common misconception
The sample rate and resolution of samples adjusts based on the sound that is being digitsed.
The digitsation of sound needs to be consistent so that the binary sequence represented can be processed as expected.
Teacher tip
The approximation of determining samples should be modelled. Talk through the process of deciding the nearest sample where the measurement falls between two values.
Licence
except where otherwise stated. See Oak's terms & conditions (Collection 2).Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is a bitmap image?
Q2.Put these elements in order from smallest to largest:
Q3.What is the term for facts and figures in their raw form?
Q4.What term describes the total number of pixels in an image based on its width and height?
Q5.What is a trade-off in image design?
Q6.What happens if you increase the resolution of an image?
Assessment exit quiz
6 Questions
Q1.What is a sample in the context of sound digitisation?
Q2.What does digitisation mean?
Q3.What is sample rate?
Q4.What happens if you increase the sample rate of a sound file?
Q5.What is measured in hertz (Hz) during sound digitisation?
Q6.Why must the sample rate and resolution remain consistent during digitisation?
To help you plan your 10 computer science lesson on: Representing sound, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 computer science lesson on: Representing sound, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 computer science lessons from the Representation of text, images and sound unit, dive into the full secondary computer science curriculum, or learn more about lesson planning.