Storing Sound Flashcards
How is sound recorded
By a microphone as analogue signal
What is an analogue signal
Pieces of continuously changing data
How can computers read and store sound files
Analogue signals are converted into digital data
How are Analogue signals converted into digital data
By Analogue to digital converters
Found in most modern devices
What is the process of converting analogue signal to digital data called
sampling
How are analogue recordings converted into digital data
The amplitude (height of the sound wave) is sampled at regular intervals. The amplitude can only take certain values depending on the bit depth
What happens once device sampled recording
It creates curve digitally, where each block of data matches where each sample was taken
What is a downside of digital data
Despite having the same shape as analogue wave it is not continuous. A lot of data is lost. Peaks in analogue waves is much flatter in digital data
How can digital data be improved
By taking samples more regularly- most music isn’t sampled every second but every millisecond
What is the sample rate/sample frequency
How many samples you take in a second
measured in hertz(hz) or kilohertz(kHz)
Bit depth
number of bits available for each sample
How is size of sound file calculated
File size (in bits)= sample rate (in hz) x bit depth x length (in seconds)
What does increasing sample rate mean
Analogue recording sampled more often. Sampled sound would be better in quality % more closely match original recording
What does increasing bit depth mean
Digital file picks up quieter sounds even if happening at same time as louder ones. Will result in sampled sound closer to quality of original recording
What is the con of increasing bit depth or sample rate
Increased file size
