"signals processed in this manner are a sequence of numbers that represent samples of a continuous variable in a domain such as time, space, or frequency"

notes about what i found important knowledge for sound creation

• online book: the scientist and engineer's guide to digital signal processing
• online book: spectral audio signal processing by julius o. smith iii
• sound texture perception via statistics of the auditory periphery: evidence from sound synthesis. synthesis of sound textures
• puredata graphical dsp programming. easy to create graphical interfaces with controls, for example when linking multiple midi devices

• analysis and resynthesis
• convolution
• frequency filtering
• notes
• phase generation
• tools used by sph
• software implementation
• synthesis

a common format for storing signals digitally is sample values of the distance magnitude of a vibration over time, like positions of a membrane between two bounding values

• stateless: have only parameter values that need not be kept
• stateful: have parameters for values that need to be kept between function calls. for example, carryover values that fall outside the currently processed range and are used in the next one
• processing one input sample at a time: can affect multiple samples only with state and delay after accumulating samples
• segment to segment: processors might depend on preceding or following values
• one to many: output creates a longer signal
• many to one: a longer signal becomes a shorter one

• analog hardware devices for synthesizers with keyboards or sequencing
• software sequencers where instruments, synthesizer sounds, recordings and effects can be layed out and played back
• software environments like fruity loops, reaktor, reason and others
• lv2 or vst plugins as effects and synthesizers
• taking audio recordings and prepare their ordered playback in a program like ardour or cubase
• connecting hardware devices with midi and puredata and the user interfaces that it can create
• preparing sample arrays using a general purpose programming language and writing to sound files

• harmonic: a harmonic is a wave with a frequency that is a positive integer multiple of the frequency of the original wave
• time series: a series of data points indexed (or listed or graphed) in time order. most commonly, a time series is a sequence taken at successive equally spaced points in time
• a sound program is a potential for sounds to occur. elements can appear and disappear like entering and exiting a dimension. there is always some kind of seed, for example the literal arguments in program code
• amplitude: the magnitude of the difference between a variables extreme values. the amplitude of a periodic variable is a measure of its change over a single period
• clipping: limiting values to a maximum
• digital image processing is a subcategory of digital signal processing
• envelope: a path of loudness transition
• every linear time-invariant system can be represented by a convolution
• frequency: number of occurrences of a repeating event per unit time
• low frequency: less rapid change between sample values
• phase: relative shift or progression of a repeating event
• sequencer: configures the starting points and durations of sounds
• vocoder: splits into frequency bands and removes bands
• wave < instrument < composition
• artificial reverberation
• beat interference pattern between two sounds of slightly different frequencies