Sound Quality

By Matt Wright

Sample Rate

Sample rate is used when compressing audio. It is essentially how often the computer samples the sound in a unit of time. For example if you sample something 8,000 times per second (H3) the output audio would be extremely low quality. However if compress something at 48,000H3 per second the quality will be much higher.

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This diagram shows a sample rate of an audio file. The curves show where the sound has been sampled.

Bit Rate

Bit rate is also used when compressing audio. Bit rate is how many different levels the points can go at (rate if compression used to encode a file). For example this diagram has a bit rate of 35kbps.
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This is very low quality. The most common bit rate is 128kbps but that doesn't necessarily produce the best sound quality. 320kbps or higher is the bit rate used in cd's, iTunes music etc.

If a song is recorded at say 128kbps, if you upgrade it to 320kbps the sound quality will stay exactly the same because you can't change the bit rate it was recorded in.

How can bit rate be represented in binary

Bit rate can be represented in binary by having binary at each sample rate. For example, the middle point on 8-bit binary would be 00000000 & the top point would be 11111111