Piero Pierucci, '93

Digital sound processing: techniques and applications
Franco Angeli, Milano, 1993,

Sound perception is a phenomenon mostly unknown, which only recently has been particularly addressed as an important field of technical and technological studies. Using computers it is now possible to modify in deep the sound structure and spatial distribution, affecting sound perception by human listeners. It is now possible to recreate artificial listening environments, almost perfectly restore damaged recordings, or synthesize a signal that is practically indistinguishable from a human voice in a chamber choir. Among the possible applications, those related to the artistic filed most benefits from this augmented knowledge about our auditory perception system, and particular emphasis is given on most recent applications in the filed of music.

The first time I was in the Peten Forest, Guatemala, we were walking towards Tikal, seeking for the Maya beauties. In this scenario I was wandered by the sounds of the forest. Literally a choir of several voices, mostly birds as the tropical parrot or the quetzal......

Air is like a sea of particles were we "swim". Each movement that physically displaces the particles, starts a "chain reaction" that possess wave-like characteristics. If we play, for instance, the string of a violin the waves may propagate to a distance and be perceived by a listener, passing through air or other sound conduction media.........

Digital means discrete, for instance it is told of something that may assume only a limited set of values. Alphabet uses a limited set of symbols, but nonetheless we are able to use it in an infinite number of combinations. A sound wave, if converted to an electrical signal using a microphone, could be digitized and stored in a computer's memory, through a process called analog to digital conversion. The inverse, digital to analog, recreates an electrical signal from a sequence of numbers, and this could be sent to a power amplification and loudspeaker set to be listened. The transformation to digital allows for several new and unprecedented ways of manipulating the sound....

In the field of music the use of computers is widespread since 80's. Well known electronic music composers started to experiment with the use of computers as early as 1968, experiencing new ways of musical creation. Since then new musical instruments, based on digital techniques, conditioned the development of new pop musical experiences with some commercial success, namely house, techno....

music

For more info on the book or comments to the author click on