In the previous paragraph we saw how the flow of atmospheric pressure in relation to the active loudspeaker can be visualized as a waveform. Waveforms can actually be very complicated, but fortunately every single one of them, and I mean every single one, can be considered as an extension of a very simple wave form: the sinusoid

In this section we'll be taking a look at the way sound behaves when it interacts with obstacles that find themselves upon its path. Generally speaking the material the obstacle is made of and its dimensions make a difference with regards to the actual nature of the interaction that occurs as much as the sound frequency contents we're looking at does.

Optical connections are generally used for the transmission of digital signals. The scheme of this kind of connection includes a LED, an optic fibre and a photo-diode, as in the following diagram