KS3 Computing/Sounds

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Links with Mathematics[edit]

  • Harmonics

Natural & Artifical Systems[edit]

Representations of sound[edit]

Analogue[edit]

In analogue recordings, the machine is always recording any sound or noise that is coming through the microphones.

Example Wave

In digital recording, however, you don't have a constant recording of what's going on. Instead, you have a series of samples taken from the sound being recorded.

WaveSampling


Think of it like a movie — a motion picture strings together a series of pictures to make it look like moving action. In this case, digital recording takes a series of "pictures" of what the sound is like and turns it into a digital recording. A standard compact disc contains sound that has been sampled at 44.1 kHz, or just over 44,000 times a second (that's a lot of pictures!). However, you may run into digital sound used by professional sound engineers in the music industry that's been recorded at 48 kHz, 96 kHz, or even higher. Just think of it as getting more detail from more pictures.

Digital[edit]

Wave Sampling illustration

Conversion of Analog to Digital[edit]

Manipulation of sound[edit]

Digital Literacy[edit]

Q When you buy a CD how many songs are there on it?

A About 10 maybe 15...

So if an audio CD has approximately 600Mb of data then each song is maybe 70Mb

Q How large is the average MP3 that you download from iTunes or Amazon?

A About 4Mb maybe as much as 10Mb for a long one

Do the two files sound the same?

What are the advantages and disadvantages of a CD quality sound file over a MP3 one you might have on your mobile phone

Resources[edit]

Programming[edit]

Manipulation[edit]

Content[edit]

Copyright of audio

Creative Commons Audio