4.5.6.7 Digital representation of sound Flashcards
What is sampling rate?
The number of samples per second, how often samples are taken
Humans can frequencies around 20,000 Hz, why is a sampling rate of 44,000 Hz used in a recording?
Because according to Nyquist’s theorem, the sample should be at least double the highest frequency of the original sound. It is slightly more than double because some can hear higher frequencies than average. A higher sampling rate than this is pointless because people wouldn’t notice and would waste space.
What factors affect the quality of sound?
The number of times the amplitude is measured - sampling rate
The number of bits available to store the measurement - sampling revolution
What is sampling resolution?
The number of bits assigned to each sample
What is Nyquist theorem?
the sampling rate must be at least twice the highest frequency in analog-to-digital conversion.
What is bit rate?
the number of bits required to store 1 second of sound
How do you calculate sound sample sizes in bytes?
File Size = (Sample Rate * Sample Resolution * Length of sound) / 8
or File Size = (Bit Rate * Length of sound) / 8
