Modulation

Disciplines of Study [DoS]  >  Acoustics  ]

The process by which one signal is used to modify another. The controlled signal is referred to as the ’carrier’, and the controlling signal as the ’modulator’. It is of the greatest importance in both sound synthesis and signal processing.

The two main parameters of a sound to which modulation is commonly applied are those of amplitude (loudness) and frequency. Amplitude modulation of a signal causes changes in loudness in that signal. If the control signal is a slow regular waveform (e.g. a sine wave) the result is a tremolo - similar to (and often confused with) vibrato, except that there is no pitch deviation. Once the frequency of the modulator is raised above 10 to 15 Hz the tremolo amalgamates into a complex sound with added frequency components derived from the pitches of carrier and modulator. An irregular or transient control signal is generally associated with envelope generation.

Frequency modulation causes the pitch of the carrier to rise and fall according to the shape of the modulating waveform. If this is, as above, a slow regular waveform, the result is vibrato if the depth of the modulation is low, otherwise becoming a wide siren-like effect. If the modulating waveform is a series of discrete steps, the result is a series of discrete pitches. Particularly complex sounds arise when the frequency of the modulator is close to or even higher than that of the carrier. (Source - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.)

Ring modulation allows for the sum and difference of two input frequencies to be combined to create a new sound. Often one of these frequencies is at a sub-audio level allowing the creation of a sound of two similar frequencies, frequently with noisy textural characteristics.

 

See also:

Amplitude, Frequency, Frequency Modulation Synthesis

 

Bibliography:

English - Español - Français - Deutch - Italiano

Alphabetical order - Chronological order

Geslin, Yann (2001). Le studio 123
Lai, Antonio (1999). La fonction compositionnelle des modulateurs en anneau dans {Mantra} (Karlheinz Stockhausen)
Moles, Abraham A. (1957). Machines à musique. L’apport des machines électronique et électroacoustiques à la nouvelle sensibilité musicale.
Pottier, Laurent (2003). {Straps} : pièce d’Eryck Abecassis pour ensemble et électronique en concert
Risset, Jean-Claude (2005a). Sur l’impact de l’œuvre scientifique, technique et musicale de John Chowning

Top

canadian pharmacies nexium clomiphene 50mg enalapril 10mg w 925 in california more purchase piracetam buy pelosta-5 in mayami http://www.actuabd.com/?order=423348 bupropion deutschland in mayami buy bactrim f cilostazol 50mg tablets bactrim for bronchitis purchasing naltrexone rifaximin 200mg tablets order vilitra http://www.actuabd.com/?order=12177 naltrexone uk no prescription aldactone sustanon 500 premarin generic flagyl online no prescription http://www.actuabd.com/?order=763439 zocor generic in canada flonida for sale sorafenib cost amitriptyline cost in california order nodict lipitor generic pharmacy norvasc tablet in mexico bupropion hcl oral information about buy fincar 22.50 prilosec cost about azithromycin over the counter azithromycin cheap http://www.actuabd.com/?order=74860 nizonide for sale clomiphene citrate tablet information prilosec lowest price sale waklert 150 quetiapine 1300 mg uk accutane dapoxetine quick ship buy bulk piracetam information order lasix ranitidine 150mg simvastatin 10 mg http://www.actuabd.com/?order=62326 information about buy doryx 150 mg online where to buy andriol testosterone pills http://www.actuabd.com/?order=986254 malegra dxt plus in california http://www.actuabd.com/?order=534570 about sustanon deca tadaga 10 eriacta in mayami 10mg amitriptyline cheap flagyl buy nuvigil mexico in new york buy pletoz usa information about revlimid 25 mg buy pelosta finasteride amitriptyline hydrochloride himalaya garlic tablets