Data Representation CS Thinking Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

medium
Sound is analogue but computers are digital. Describe how analogue sound is converted to digital form, using the terms 'sample rate' and 'bit depth'.

Solution

  1. 1
    Step 1: The analogue sound wave is measured (sampled) at regular intervals. The sample rate is how many times per second the wave is measured (e.g., 44,100 Hz for CD quality).
  2. 2
    Step 2: Each sample's amplitude is rounded to the nearest value that can be represented with the given bit depth (e.g., 16-bit gives 65,536 possible values). Higher sample rate and bit depth give better quality but larger files.

Answer

Sound is sampled at regular intervals (sample rate) and each sample is stored with a fixed number of bits (bit depth). Higher values = better quality but larger files.
Analogue-to-digital conversion involves sampling and quantisation. This is why audio quality settings exist — they trade file size for sound fidelity.

About Data Representation

The way information—numbers, text, images, and sound—is encoded as binary digits (0s and 1s) inside a computer. Different encoding schemes map real-world data to binary patterns, such as ASCII/Unicode for text, RGB for colors, and sampling for audio.

Learn more about Data Representation →

More Data Representation Examples

Example 1 easy

A computer stores the character 'A' as the number 65 (ASCII). Explain why computers use numbers to r

Example 2 medium

Explain how a computer represents a colour image using binary. What are pixels and colour depth?

Example 4 hard

Explain the difference between lossless and lossy compression. Give an example of each and explain w

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