Sound

How is sound sampled

Measuring the height (amplitude) of the analogue sound wave

2. Each measurement (sample) generates a value which can be represented in binary and stored

What converts analogue waves to digital form

Analogue to Digital conversion (A2D

Why must analogue signals be converted and what to /how

-Analgoue signals need to be converted into digital data so that computers can read and store sound files.

done by analogue to digital convertor

Process of converting analogue to digital is sampling

What is sample rate

• Sample rate is the amount of samples taken per second of the analogue wave

• Samples are taken each second for the duration of the sound

• The sample rate is measured in Hertz (Hz)

• 1 Hertz is equal to 1 sample of the sound wave

What is bit depth

• What is bit depth?

  • Bit depth is the number of bits stored per sample of sound

  • Bit depth is closely related to the colour depth of a bitmap image, they measure the same thing in different contexts

What is Duration

The length of time that the sound is sampled for, measured in seconds or minutes

How does higher sample rate affect quality and size of file

-Increasing sample rate means the analogue recording is sampled more often

-The sample sound will be better quality and will more closely match the original recording

However, increasing sample rate/but depth increases file size

How does increasing bit depth effect quality and the size of file

-Increasing the bit depth will mean the digital file picks up quieter sounds

-This will result in a sampled sound that is closer to the quality of the original recording but increase size file