Representing sound in a computer

analogue data that varies in a continuous matter

analogue-to-digital converter (ADC): to sample electrical equivalent of sound and convert sample into digital signal using two voltage level

to playback recorded sound, use of digital to analogue can vector (DAC)

PCM: form of an analogue signal is produced by an ADC

PAM: pulse aptitude modulation

formula to calculate file size:
file size = sample rate(Hz) x length of recording (seconds) x sampling resolution (Bits)

example

44,000 Hz x 60 seconds x 16 bits = 42,240,000 bits = 5,280,000 bytes
or 5.28 MB or 5.03 MiB

Nyquist's theorem

sound must be sampled at least twice its highest analogue frequency in order to extract all of information from the bandwidth and accurately represent original acoustic energy.