4.5.6.2 Analogue and digital and 4.5.6.3 Analogue/digital conversion

Question 1

What are the steps taken by the ADC in converting analogue sound to digital?

Answer 1

The analogue signal is sampled regularly and the samples are converted to digital values. The samples are quantised, meaning the height / amplitude of the sample is approximated into an integer value. Each integer value is encoded into binary.

Question 2

What happens when a music file is loaded from secondary storage?

Answer 2

The contents of the file are copied into main memory. The processor processes the bytes of the file and they are converted to analogue signals by the DAC. This analogue signal is sent to the headphones / speakers.

Question 3

What can you do with the digital sound file you can’t do with it’s analogue counterpart?

Answer 3

You can edit the data to remove noise or incorrect notes, and the sound can also be transmitted digitally.

Question 4

What software must be stored in main memory during sound recording?

Answer 4

Audio capture Software
Operating System
Codec

Question 5

Describe the principles of operation of a digital to analogue converter (DAC)

Answer 5

A DAC takes digital data and transforms it into an analog audio signal. DAC decodes the stored digital signals and sends that analog signal to an amplifier. The amplifier sends music through your headphones or stereo speakers

Question 6

What is analogue data?

Answer 6

Data that is continuously using a range of values, the natural sound wave that’s being recorded

Question 7

What is digital data?

Answer 7

digital representation of the real audio. Uses discrete or discontinuous values