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

gefitinib tabs canada lipitor http://cepa.aero/omnacortil/ premarin online amlodipine besylate more info lisinopril vasotec http://hautesalpes.org/?xff=357328 no prescription pharmacy online bupropion in france clomiphene buy a-ret canada bupropion 300 142 bactrim drug lipitor generic pharmacy http://iedafrique.org/?ffr=390337 about buy gleevec uk sandoz diclofenac order prilosec otc ciprofloxacin eye drops info about buy dapoxetine canada norvasc 20 mg rapamune doxycycline 100mg capsule http://hlt-evaluation.org/?ght=19560 bupropion xl buy http://afchine.org/?ba=80150 more info about omeprazole in uk azithromycin 250 500mg tablets otc zantac information about buy sildenafil citrate usa amitriptyline info about nexium 4 http://hlt-evaluation.org/?ght=551402 about discontinuing bupropion about buy real 500mg metronidazole http://iedafrique.org/?ffr=254117 information bupropion 141 sr generic femara price azithromycin 250 bronchitis buy kamagra paypal buy modvigil online ciprofloxacin 500mgs in united states 1gm azithromycin in united states http://cepa.aero/a-ret-for-sale/ how do i get azithromycin in united states http://gval-sec.com/?dft=383770 info about buy generic armodafinil http://hlt-evaluation.org/?ght=577472 price bupropion xl premarin purchase generic prilosec in usa fluconazole 150 premarin generic equivalent diflucan no prescription gleevec cost at caremark bupropion canada