Representing Sound
Analogue & Digital
Digital Sound
Sample Rate
Bit Depth
click to edit
Humans hear in analogue
Computers work in digital
Computers need to convert sound into digital data
click to edit
Audio is captured (Called sampling) via an input device like a microphone (Analogue device)
The computer or a specific converter changes this signal in binary ADC – Analogue to digital convertor)
Software saves the data as sound files
with the quality being determined by sample rate, bit depth and bit rate.
click to edit
Sample rate is how many samples, or measurements of the sound are taken each second
Measured in Hertz (Hz)
More samples = more accurate reproduction = better quality = larger file sizes
click to edit
Bit depth is the number of bits available for each sample
The higher the bit depth, the higher the quality of audio
E.G. CD = 16 bits, DVD = 24 bits
16 bit has a resolution over 65 thousand
possible values and 24 bit has 16 million
Audio files are encoded (saved) as particular file types.
Bit Rate
click to edit
The bit rate tells us how many bits of data a processed every second
Usually measured in kilobits per second (kbps)
The higher the rate the more realistic the sound
click to edit
Computers process audio in digital format our ears need analogue
An input device is needed to capture and a converter to change it into digital
Sample rate = how many samples per Second
Bit depth = how many bits per sample
Bit rate = the number of bits required to store 1 second of sound.
click to edit
click to edit
click to edit