Musical signal processing with labview  (Page 2/6)

Learning module collections

• LabVIEW Programming Techniques for Audio Signal Processing -- After completing this course you will be well-equipped to start creating your own audio and signal processing applicationswithin the LabVIEW development environment. The course includes a "Getting Started" tutorial, editing tips, essential programming structures, subVIs, arrays, audio sources, audio output to the soundcard, reading and writing audio files, and real-time audiooutput with interactive parameter control.
• Introduction to Audio and Musical Signals -- Learn about human perception of sound, including pitch and frequency, intensity and amplitude, harmonics, and tuning systems.The treatment of these concepts is oriented to the creation of music synthesis algorithms. A hands-on project investigates the specific choice of frequencies for the tuning system called "equal temperament," the most common tuning system for Western music.
• Analog Synthesis and Modular Synthesizers -- Analog modular synthesizers popular in the 1960s and 1970s produce sound with electronic devices such as oscillators,amplifiers, filters, and envelope generators linked together by cables. A specific cable configuration (or "patch")produces a distinct sound controlled by a keyboard or sequencer. While digital synthesis has largely replaced analog synthesizers, the concepts and techniques of analog synthesis still serve as the basis for many types of synthesisalgorithms. Learn about modular synthesizers and use LabVIEW to compose a piece of music by emulating an analog synthesizer.
• MIDI for Synthesis and Algorithm Control -- The Musical Instrument Digital Interface (MIDI) standard specifies how to convey performance control informationbetween synthesizer equipment and computers. Standard MIDI files (.mid extension) include timing information with MIDI messages to embody a complete musical performance. Learn about the MIDI standard, discover useful MIDI-relatedsoftware utilities, and learn how to use LabVIEW to create a standard MIDI file according to your own design that can be played by any media appliance. Also learn about "MIDI JamSession," a LabVIEW application VI thatrenders standard MIDI files to audio using "virtual musical instruments" of your own design.
• Tremolo and Vibrato Effects (Low-Frequency Modulation) -- Tremolo and vibrato add interest to the sound of musical instruments and the singing voice. Tremolo is a low-frequencyvariation in amplitude, while vibrato is a low-frequency variation in frequency. Learn how to model each of these effects mathematically, and discover how to implement these effects in LabVIEW.
• Modulation Synthesis -- Amplitude modulation (AM) and frequency modulation (FM) are familiar types of communications systems. When themodulating frequency is in the audio range, AM (also called ring modulation) produces interesting special effects by shifting the source signal spectrum, and can be used to raise or lower the pitch of an instrument or voice. FM creates rich,time-varying spectra that can be designed to emulate the sound of many different musical instruments. Learn about the mathematics of AM and FM, and learn how to implement these modulation schemes as audio signal processors and music synthesizers in LabVIEW.
• Additive Synthesis -- Additive synthesis creates complex sounds by adding together individual sinusoidal signals called partials.A partial's frequency and amplitude are each time-varying functions, so a partial is a more flexible version of the harmonic associated with a Fourier series decomposition of a periodic waveform. Learn about partials,how to model the timbre of natural instruments, various sources of control information for partials, and how to make a sinusoidal oscillator with an instantaneous frequency that varies with time.
• Subtractive Synthesis -- Most musical instruments as well as the human voice create sound by exciting a resonant structure or cavity by a widebandpulsed source. The resonant structure amplifies select frequency bands (called formants) and suppresses (or "subtracts") others. Subtractive synthesis algorithms use time-varying sources and time-varying digital filters to model physical instruments.Learn how to use the DSP capabilities of LabVIEW to implement an interactive time-varying filter, a band-limited wideband source, a vowel synthesizer for speech, a "cross synthesizer" in which a speech signal's spectral envelope issuperimposed on a musical signal, and a remarkably life-like plucked string sound.
• Sound Spatialization and Reverberation -- Reverberation is a property of concert halls that greatly adds to the enjoyment of a musical performance.Sound waves propagate directly from the stage to the listener, and also reflect from the floor, walls, ceiling, and back wall of the stage to create myriad copies of the direct sound that are time-delayed and reduced in intensity.Learn how to model a reverberant environment using comb filters and all-pass filters, and how to implement these digital filters in LabVIEW to create an audio signal processor that can add reverberation an audio signal.In addition, learn how to place a virtual sound source in a stereo sound field using interaural intensity difference (IID) and interaural timing difference (ITD) localization cues.