Sound and Memory units

Question 1

What is an ADC?

Answer 1

Analogue-to-digital converter

Samples and converts an analogue signal into an equivalent digital signal

Question 2

What is a DAC?

Answer 2

Digital-to-analogue converter

Converts a digital signal into an equivalent electrical analogue signal

Question 3

Analogue signal

Answer 3

cover a whole continuous range of values

Question 4

Digital signal

Answer 4

change in discrete steps

only have two values off (0) and on (1)

Question 5

sample rate

Answer 5

The number of samples taken per second of sound

Question 6

sample resolution

Answer 6

The number of bits used to store each sample(measurement of the height of the wave)

e.g. bit depth

Question 7

bit rate

Answer 7

Sample Rate x Sample Resolution

number of bits required to store 1 second of sound

Question 8

higher sample rate and sample resolution

advantage

Answer 8

better quality music

Question 9

higher sample rate and sample resolution

2 disadvantages

Answer 9

more bandwidth required for transmission

more memory space required for storage

Question 10

5 Advantages of digital sound

Answer 10

It can be edited and manipulated easily by computer equipment.
It is more portable
It can be played over and over again without deterioration.
It can be easily copied on a computer.
Digital audio files can be easily emailed, downloaded and streamed by users.

Question 11

How are analogue sounds recorded in binary?

Answer 11

The amplitude (height) of the wave is measured and sampled at regular intervals
How often the height is measured is known as the sample rate
The sample resolution is the number of bits used to measure the height

Question 12

MIDI

Answer 12

Musical Instrument Digital Interface
Communication protocol that allows electronic musical instruments to communicate with each other
8-bit serial transmission (asynchronous)

Question 13

5 example MIDI commands

Answer 13

Instrument - which instrument is being played.
Pitch - frequency of the note
Volume - how the note is played loud or soft.
Duration - length of the note (on and off)
Tempo - speed at which the music is played

Question 14

4 advantages of MIDI

Answer 14

File sizes are smaller
All aspects of the sound can be edited
Effects can be applied to individual instruments
No interference or background noise during recording

Question 15

4 disadvantages of MIDI

Answer 15

Dependent on quality of sound card for overall sound
Can not store vocals
Effects are limited
Less realistic sounds than actual instruments

Question 16

List all of the memory units in descending (largest to smallest) order of size

Answer 16

terabyte (TB)
gigabyte (GB)
megabyte (MB)
kilobyte (KB)
byte
nibble
bit

Question 17

How many bytes in a Terabyte?

Answer 17

2^40 bytes