01 Represetning Sound Flashcards
1
Q
Examples of ADCs and DACs
A
ADC - microphones
DAC - speakers
2
Q
Analogue to digital conversion
A
- analogue sound samples are recorded via an amplifier
- each sample is quantised to measure its wave height and translate this into an integer value
- the internet value is sorted as binary value
- to output a sound, the reverse happens
3
Q
Sampling
A
An analogue signal is measured at regular periods
4
Q
Amplitude
A
Referred to as the sample resolution
5
Q
Sample resolution
A
Referred to as the sample rate and is measured in hertz
Then number of bits used o records each measurement
6
Q
Affect of frequency
A
The greater the frequency, the greater the accuracy and file size
7
Q
File size (audio file)
A
File size = sample rate x resolution x length in seconds
8
Q
Nyquist theorem
A
Nyquist rate: Sample rate = 2 x maximum frequency
Therefor
Nyquist frequency: ½ the original frequency
