This key facts covers Sound File Size Calculation within Images & Sound for GCSE Computer Science. Revise Images & Sound in Memory & Storage for GCSE Computer Science with 18 exam-style questions and 16 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 8 of 11 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 8 of 11
Practice
18 questions
Recall
16 flashcards
Sound File Size Calculation
Formula:
File Size (bits) = Sample Rate × Bit Depth × Duration × Channels File Size (bytes) = (Sample Rate × Bit Depth × Duration × Channels) ÷ 8
Example 1: CD Quality, 1 Second
Sample Rate: 44,100 Hz
Bit Depth: 16 bits
Duration: 1 second
Channels: 2 (stereo)
File Size = 44,100 × 16 × 1 × 2
= 1,411,200 bits
= 1,411,200 ÷ 8
= 176,400 bytes
≈ 172 KB per second
For 3-minute song: 172 KB × 180 seconds = 30,960 KB ≈ 30 MB
Example 2: Telephone Quality, 10 Seconds
Sample Rate: 8,000 Hz
Bit Depth: 8 bits
Duration: 10 seconds
Channels: 1 (mono)
File Size = 8,000 × 8 × 10 × 1
= 640,000 bits
= 640,000 ÷ 8
= 80,000 bytes
= 80 KB
Example 3: Comparing Quality Levels
Same 1-second recording at different qualities: Telephone (8kHz, 8-bit, mono): 8,000 × 8 × 1 × 1 ÷ 8 = 8,000 bytes = 8 KB/sec CD Quality (44.1kHz, 16-bit, stereo): 44,100 × 16 × 1 × 2 ÷ 8 = 176,400 bytes = 172 KB/sec CD is 21.5× larger than telephone!