Sampling Theory Flashcards
How is digital audio stored?
In binary code: 1=on 0=off
What is the rate of capturing and playback?
Sampling rate
What is the sample rate?
The rate of capture and playback.
What is the bit rate?
The number of times a second it is carried.
What is the length of binary code?
Bit-depth
What is bit-depth?
Length of binary code.
How will the data change with a higher resolution?
More data will be captured to more accurately re-create the sound, achieving a better quality.
What can bit-depth also determine?
The dynamic range of the signal.
What is the redbook standard?
44.1Hz / 16-bit
What is Nyquist Theorem?
In order to accurately reconstruct a signal of a specific bandwidth, the sampling frequency must be greater than twice the highest frequency of the signal being sampled.
What can occur is sampling frequency is too low?
Aliasing distortion.
What is aliasing distortion?
High-frequencies of the signal become indistinguishable with lower-frequencies.
What are the advantages of a lower bit-depth?
Reduce signal-to-noise ratio, gives a brittle/ crunchy sound.
Sought after in lo-fi recordings.
What is quantising?
the closest replication of an analogue waveform digitally. It replaces each real number with an approximation from a finite set of discrete values.
What is pitch mapping?
Laying a sample across multiple keys and changing the playback speed and pitch to match the 12 notes of the scale.
What is multisampling?
Assigning each sample to one or multiple keys.
What is velocity layering?
Different samples are assigned to different velocity ranges triggered by MIDI velocity
What is one-shot sampling?
Short audio samples that aren’t looped or have tempo markings
What is looping?
Creating a more sustained sound or a groove, beginning and end is placed on zero crossings to avoid glitches or clicks.
What is truncating?
Editing start and end points for a clean sample
What is time-stretching?
Changing length of sample without altering the pitch.
