Digital Sound
Digital sound is made by measuring a sound wave at regular intervals and storing the measurements as binary numbers.
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Play with the controls to see the idea in action.
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Digital sound is made by measuring a sound wave at regular intervals and storing the measurements as binary numbers.
- Sample rate is samples per second
- Higher sample rate gives better quality
- Bit depth affects accuracy
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Digital Sound?
Within Computer Science, which covers algorithms, programming, data, networks, hardware and safe, responsible use of technology, this topic explains Digital Sound. Computing topics explain how software, hardware and data work, with diagrams and models that show each step in order.
Check that you can explain Digital Sound in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Digital Sound helps you design, test and explain programs, websites and systems, from small projects to exam questions.
Digital Sound in detail
Sound is a continuous analogue wave, so computers convert it to digital data by sampling: measuring the amplitude at regular intervals. The sample rate (samples per second, in Hz, such as 44,100 Hz for CDs) and the bit depth (bits per sample) decide the accuracy of the digital version. Higher values give better quality, but a bigger file.
File size = sample rate × bit depth × duration × channels. Compression, such as MP3 (lossy), reduces the size by removing sounds that are hard to hear. Digital sound is easy to copy, edit and send without loss, and is used in music, voice assistants and calls.
How the interactive helps you understand Digital Sound
Watch the wave in the interactive. Use any sliders or buttons it offers to change the values and see how the wave responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Digital Sound.
Real-life uses and examples
- Trace through a process that uses Digital Sound to check what it does step by step.
- Recognise Digital Sound in an app or device you use every day.
- Apply Digital Sound when you design a small program, website or spreadsheet.
Common mistakes to avoid
- Testing only the normal case and forgetting the edge cases.
- Using the term without being able to say what the computer actually does.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Digital Sound
What is Digital Sound?
Digital sound is made by measuring a sound wave at regular intervals and storing the measurements as binary numbers.
What are the most important points about Digital Sound?
The main points are: Sample rate is samples per second; Higher sample rate gives better quality; Bit depth affects accuracy.
Why is Digital Sound useful?
Understanding Digital Sound helps you design, test and explain programs, websites and systems, from small projects to exam questions.
How can I practise Digital Sound?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Digital Sound?
Related topics in Computer Science include Alan Turing and Ada Lovelace, Game Design, Accessibility in Technology.