Digital Representation of Sound

Question 1

Define Amplitude

Answer 1

-Height of the wave
(middle to its highest point)
-Shows Volume

Question 2

Define Time Period

Answer 2

Time that passes between two wave peaks

Question 3

Define Frequency

Answer 3

• 1/Time Period

- Shows Pitch

Question 4

Define Process of ADC

Answer 4

Analogue to Digital Converter:

• Pick up sound waves on microphone
• Converts to analogue electrical signals
• Sampling, takes measurements of the level of the analogue signal at regular time intervals (samples)
• Assigned Binary Pattern and Stored

MASLRBS
Mike Always Signals Left Right Before Speeding

Question 5

Define Process of DAC

Answer 5

Digital to Analogue Converter:

• Convert digital values to analogue electrical signals
• Passed to Speaker
• Creates Analogue Sound Waves

DASW
Darcy Always Speeds Willingly

Question 6

Define Sampling Rate

Answer 6

• Frequency used to sample an analogue signal
• Number of samples taken per second (Hertz)
• Higher sampling rate = better quality and bigger file size

Question 7

Define Sample Resolution

Answer 7

• Number of bits used to represent each sample

- Lower Sample resolution = available binary patterns will be very limited, variation will not be represented accurately

Question 8

Define Nyquist Theorem

Answer 8

Sampling rate must be at least the highest frequency present in the sample to have an accurate representation of a signal

Question 9

Define Mono

Answer 9

One track of sound

Question 10

Define Stereo

Answer 10

• Two different tracks (impression of positioning and direction)
• Doubles storage space required

Question 11

How do you calculate the storage requirements for audio files

Answer 11

Storage Requirement = sampling rate x seconds x sample resolution

(x2 IF STEREO)