Sound Flashcards
Analogue sound signals are
Continuous
Discrete signals are
Discrete and not continuous
How is sound digitised
By repeatedly measuring and recording the sound wave
What is used to convert sound inputs to digital signals
An ADC analogue to digital converter
What is used to convert digital signals to outputs
A DAC digital signals to output
What is a sound sample
Is a measurement if amplitudes of a sound wave at a given time, and it is sampled using a bit depth and sample rate
What is the unit of sample rate
It is measured in Hz or kHz
What is a sound resolution
The number of bits used to record each measurement
What is the affect of sample rate
When we increase the sample rate, the accuracy and file size increase too.
How do we calculate sound files
File Size=
sample rate × resolution × duration
What does Lossy compression do in audio
It removes sounds that we can’t easily hear, or that least affect perceived playback quality
What is lossy compression useful for
Downloading, storing or streaming audio
What does lossless compression do
Reduce file size when compressed but do no lose any information
Examples of lossless music file formats
FLAC (free lossless audio codec)
ALAC (apple lossless audio codec)
WMA lossless (windows media audio)
