Unit 1 - Chapter 2 - Analogue and Digital

Question 1

How are analogue signals sampled?

Answer 1

Signal voltage is measured at equal time intervals (sampling rate)
This measurement is converted to a binary number
Digital number store to transmitted to a receiver
When sound is player binary data is reconverted to an analogue signal to drive loudspeaker.

Question 2

What is bit rate?

Answer 2

Bit rate is the number of bits of encoded data which represents a piece of music in a given time.

Lower bit rate = less faithful to original audio

1 digit is a bit
8 digits are a byte

Question 3

What is the difference between an Analogue and Digital Signal?

Answer 3

Analogue signals vary continually with time, the value at any given time is directly proportional to a physical quantity.

Digital signals are binary coded in pulses of voltages of light using quantisation.