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

enalapril malleate zocor http://penclub.fr/?hah=2758 buy apcalis canadian nexium buy lovegra in australia http://www.revue-medias.com/?dft=1867 florida accutane fluconazole 150mg amlodipine discounts more info about purchase bactrim online in us ciprofloxacin hct http://tg.auf.org/?har=900503 naltrexone mg no prescription voltaren sr aldactone 100mg in mayami over the counter zantac amisulpride online buy ampicillin online generic femara tab 2.5mg over the counter orlistat 60mg more lipitor in ontario http://onpes.gouv.fr/?gav=938058 information about premarin .625 buy levitra 10 mg http://www.stop-it.it/spip.php?asr=15155 information nexium caps http://penclub.fr/?hah=81204 vasotec non perscription http://tg.auf.org/?har=241328 wellbutrin sr amitriptyline 50 tadalafil 40 mg buy viread buying doxycycline in mexico http://telegramme228.com/svn.php?ssf=596264 penegra pills enalapril over the counter without prescription http://theatre-bourg.com/?fga=394526 cheapest nexium in usa purchasing letrozole armodafinil generic doxycycline 100 in mexico ciprofloxacin mexico orlistat non prescription http://www-lisic.univ-littoral.fr/?zx=473422 quinine sulphate 300 mg tablets http://onpes.gouv.fr/?gav=204717 piracetam for sale in uk pricing lipitor in uk viread in mayami buying piracetam http://www-lisic.univ-littoral.fr/?zx=122605 low cost piracetam more norvasc tablet