Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Computer Science
Lesson Topic: Show understanding of how sound is represented and encoded
Learning Objective/s:
  • Describe how analog sound waves are converted to digital audio via sampling and quantisation.
  • Explain the relationship between sample rate, bit depth, and audio quality/dynamic range.
  • Compare lossless and lossy audio compression formats and select appropriate formats for given requirements.
  • Calculate the data rate and file size of uncompressed PCM audio.
  • Apply the PCM encoding process to create a simple audio file using a chosen sample rate and bit depth.
Materials Needed:
  • Projector and screen for slides
  • Whiteboard and markers
  • Computer with audio editing software (e.g., Audacity) and internet access
  • Sample audio files in WAV, MP3, and FLAC formats
  • Handout summarising sampling, bit depth, and compression concepts
  • Worksheets for calculation exercises
 Introduction:
Begin with a short clip of a high‑fidelity recording followed by the same clip compressed as MP3 to spark curiosity. Review prior knowledge of binary representation and ask students how sound can be stored digitally. Explain that by the end of the lesson they will be able to describe the encoding process, compare formats, and perform basic size calculations.
Lesson Structure:
  1. Do‑now (5'): Quick quiz on binary numbers and analog vs. digital signals.
  2. Mini‑lecture (10'): Explain sampling, Nyquist theorem, and bit depth with diagrams.
  3. Demonstration (10'): Show ADC process using Audacity – import a tone, view waveform, change sample rate/bit depth, export as WAV and MP3.
  4. Guided practice (12'): Students calculate data rate and file size for a 3‑minute stereo track using the provided formula.
  5. Group activity (10'): Compare audio files (WAV, FLAC, MP3) for quality and size; discuss lossless vs. lossy.
  6. Check for understanding (5'): Exit ticket – one sentence describing why 44.1 kHz is standard for CD audio.
Conclusion:
Summarise how sampling rate, bit depth, and compression determine audio quality and file size. Collect the exit tickets and clarify any remaining questions. For homework, students record a 10‑second voice clip, experiment with two different sample rates and bit depths, and write a brief reflection on the audible differences.