From Latin modulatio, the term modulation is related to the fact and consequences of modular . This verb has several applications and uses, such as altering the properties of a sound, changing the factors that affect a procedure to achieve different results, leaving a hue to appeal to another or modifying the value of a frequency , phase or amplitude of a wave.
For the telecommunications , the modulation are those techniques that are applied in the transport of data on carrier waves . Thanks to these techniques, it is possible to take advantage of the communicative channel in the best way to transmit a greater flow of data simultaneously. Modulation helps protect the signal from interference and noise.
The modulation process consists in varying a parameter that is in the carrier wave depending on the alterations of the modulating signal. You can talk about frequency modulation , amplitude modulation , base modulation and wavelength modulation , among other types.
In the musical field, modulation consists of alter the tone momentarily, so it should not be indicated in the score with a new key armor, and it is possible to solve it by means of a cadence, although it is not mandatory. In general, it is sought to move to nearby shades (not to be confused with physical proximity of the notes in a staff, but that they are related in some direct way and that require the least amount of changes or "accidents"starting from the main one), although sometimes it is sought to change mode (from major to minor or vice versa) or by different intervals.
The three types of modulation that are currently taken into account are explained below:
* using a bridge chord: when it comes to tones neighbors, as explained in the previous paragraph. The idea is to start from a common chord to both shades, and then make a cadence to solve at the desired destination. The simplest case, that is, one for which no alteration is needed, is to change from a minor or major relative tone, such as from C major to minor. On the other hand, the most complex is modular to a tone that shares only a chord with the original.
* by chromatism: it consists of starting from a chord of the main tone and altering a note of chromatic form (raising or lowering half tone) to turn it into a chord of a new tone, which was not related to the first one. If, for example, it is desired to move from C major to G minor (it should be clarified that the chord of G major with its seventh minor is the dominant one of C, which means that it occupies an essential role in that tone, since there is a lot of tension between this and do, the tonic) it is possible to take a chord of Sol Mayor and then convert the yes natural (also called becuadro) in flat.
* enharmonic: It is obtained when the way of writing one or several notes of a chord is altered, even if they continue producing sounds. A practical example is writing Sustained sun as the flat that, leaving aside the particular appreciations of some string musicians, they should produce the same amount of vibrations, so that the ear cannot perceive a difference. Musically, the distance between two shades involved in this type of modulation is very large.
Finally, the voice modulation refers to the alteration of tone with harmony and softness, that is, without highlighting the ears of the listener. The announcers and the actors must be able to modulate the voice according to the genre they travel, without losing clarity in expression or elegance.