How sound can be sampled and stored in digital form

Sound: How sound can be sampled and stored in digital form

1.2.4d Data Storage: Sound

Data Storage: Sound — Note 2 of 3

What you need to know

Sound is analogue — it is a continuous wave. Computers cannot store continuous waves, so they take regular 'snapshots' (samples) of the sound wave's amplitude at set intervals. Each sample is stored as a binary number.

What to know

Sound is analogue (continuous); computers store it digitally (discrete samples).
Each sample is stored as a binary number. These binary numbers are stored sequentially to reconstruct the sound during playback.

Key terms

Analogue Sound: Sound represented as a continuous wave that varies smoothly over time.
Sample: A measurement of the amplitude (height) of a sound wave at a specific point in time, stored as a binary number.
Sampling Rate: The number of samples taken per second, measured in hertz (Hz). 1 Hz = 1 sample per second.
Bit DepthSound: The number of bits used to store the amplitude value of each sound sample when converting analogue sound into digital form. More bits = more precise amplitude values.

Exam technique

Tip:A higher sampling rate captures MORE samples per second, creating a more accurate representation of the original sound wave.
Tip:Sound sampling measures the AMPLITUDE (height) of the wave at regular intervals. It does NOT measure the frequency of the wave. This is a VERY common exam mistake.
Mistake:Saying 'the frequency of the wave is measured'. In sound, frequency relates to pitch. What is SAMPLED is the AMPLITUDE at set intervals.

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