Sound science is good to know about when recording, mixing and composing using editing software, samplers and synthesizers and today we are going back to basics to learn what sound really is.

Every sound has a source and at the source you will find that the sound is created because something has vibrated back and forth. This vibration at the sound source may not even be visible but as our source vibrates it passes this vibration onto the air around it (or whatever other matter is around it for example water).

• As our sound source vibrates forward it bumps into air molecules and pushes them closer to other air molecules, we end up getting a section of air molecules crowded closer together. This is called compression and if we were to see this on a waveform editor it is when the wave goes above the centre line (a peak).
• As our sound source vibrates backwards it pull the air molecules apart and increases the distance between our air molecules making them less crowded. These are called rarefactions and these are when the waveform goes below the centre line in an editor (a trough).

These compressions and rarefactions make up the sound wave. The best way to visualize these compressions and rarefaction is to get a slinky (Yes one of those things that "walks" down the stairs) and two people hold it at each end and spread apart. One person then compresses the end by pushing it towards the other person and you will see that sections will compress and decompress and the "message" will get transferred from one end to the other. The same way a sound moves through the air.

Sound travels in all directions from our sound source, just like when you drop a stone in water and the ripple effect goes out in all directions. Eventually it will then come to our ears. Our outer section of our ear (the bit you can see and pull) collects the sound up and helps to direct it down the ear canal. Sound travels down the ear canal and hits the ear drum (the tympanic membrane).

Just like our sound source passes on the vibration to air, air passes it’s vibration onto our ear drum as our ear drum copies the compressions and rarefactions. Our ear drums then pass this vibration message on through some tiny bones, the cochlea, hairs and some nerves to our brains, where we process the signal.

A good understanding of sound science can really help Music Creation and here at Rhythm Creation we will be bringing more articles about sound science such as what is frequency and reverberation amongst other things.

Article written by Edward Cufaude for Rhythm Creation.