Musical Acoustics – By Andrew R. Brown

Although digital instruments are not themselves vibrating bodies, they do, like all acoustic instruments, generate vibrations. Digital instrument normally create vibrations in speakers as output. Therefore, an understanding of musical acoustics and the physics of sound is important for digital instrument design and building. A digital instrument can often be understood as a virtual instrument, which uses mathematics to simulate or reproduce the effect of vibrating objects.

Sound exists as vibrations. It travels through different mediums which effect the vibrations and the ear receives those vibrations and our brain interprets them as sound. Understanding how each medium impacts upon the sound travelling through it, and how we interpret what we hear, are important for the digital instrument builder. As well as understanding how sound travels in the air, other obvious media to understand are those used in acoustic instrument, wood and metal, and their basic structures, strings, pipes, plates, bells, and so on.

The nature of the digital medium is a unique aspect of sound transformation. The basics of digital audio are covered on the audio page. The impact of the digital nature of the medium concerns the inherent quantisation process and the ability to copy the data (transfer the sound) without degradation.

Resources on musical acoustics and psychoacoustics:

http://www.phys.unsw.edu.au/music/
http://www.musictrader.com/bookacou.html
http://physics.about.com/cs/physicsofmusic/
http://privatewww.essex.ac.uk/~cplack//Psycho.html
http://sound.eti.pg.gda.pl/SRS/psychoacoust.html