All topics › Edexcel GCSE Computer Science › Sound2.2.3 SoundEdexcel GCSE Computer Science (1CP2) · Data › Data representation
Practise Sound. 12 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Build a paper on this topic ▶ Watch videos on Sound (Craig 'n' Dave Edexcel on YouTube) · Practise all of Data representation
Quick recall Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
State what is measured each time a sample of a sound wave is taken. The amplitude of the wave.
Define the term 'bit depth'. The number of bits used to store each sample. Sample questions Written for this site in the style of Edexcel exam questions. They are not taken from real past papers.
Question 1 Easy 3 marks
(a) Identify the definition of the sample rate of a sound recording.[1]
The number of samples taken each second The number of bits used to store each sample The length of the recording in seconds The loudness of the sound (b) State what is measured each time a sample of a sound wave is taken.[1]
(c) State the unit used for sample rate.[1]
Show the answer and mark scheme (a) Answer: The number of samples taken each second
(b) Answer: The amplitude of the wave.
the amplitude (height) of the sound wave Question 2 Medium 3 marks
A podcast episode is recorded with a sample rate of 44,100 Hz and a bit depth of 16 bits. The episode lasts 10 minutes.
(a) Construct an expression to calculate the file size of the episode in mebibytes (MiB).[2]
(b) The next episode is recorded with a bit depth of 8 bits. Everything else stays the same.[1]
Show the answer and mark scheme (a) Answer: 44,100 × 16 × 600 ÷ 8 ÷ 1024 ÷ 1024
44,100 × 16 × 600 (10 minutes = 600 seconds) / 44,100 × 16 × 10 × 60 ÷ 8 ÷ 1024 ÷ 1024 (b) Answer: The file size halves.
the file size halves / the file is half the size (each sample uses half as many bits) Question 3 Hard 4 marks
A voice assistant records speech at a sample rate of 16 kHz (16,000 samples per second).
(a) Calculate the sample interval in microseconds (µs). Show your working. (1 second = 1,000,000 µs)[2]
(b) The developers reduce the sample rate to 8 kHz. State the new sample interval in microseconds.[1]
(c) Give one reason why the developers might accept the lower sample rate for recording speech.[1]
Show the answer and mark scheme (a) Answer: 62.5 µs
1 ÷ 16,000 = 0.0000625 seconds 62.5 (µs) (c) Answer: Speech is still understandable, and half as much data has to be stored and sent.
speech is still clear enough to be understood, and the files are half the size / there is less data to send to the server / it is faster to process Related subtopics
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