So… What is sound ?
Well… sound by definition is a mechanical disturbance from a state of equilibrium that propagates through an elastic material medium, in more “average man’s terms” sound is the vibration of air (and other objects). Sound travels with 768 mph (1,236 km/h), it’s important to know the speed of sound because it’s one of the properties of sound that give each room or venue it’s distinctive sound (the larger the venue the more it takes for the sound to travel to and from the walls so the more echo it creates). The easiest way of representing a sound (visually) is by
Three of the most important properties of a sound wave are frequency and amplitude.
Frequency is represents the time it takes for a wave to do 360 degrees. The unit of measurement for sound is Hertz (Hz).
The in music the sound is usually split into (the list below is subjective because there aren’t any standards to define them so some people might use, for example, 10 Hz – 500 Hz as Lows) :
– Low frequencies (Bass) : 20 Hz – 300 Hz
– Middle frequencies (Mids) : 300 Hz – 2000 Hz (2 kHz)
– High frequencies (Highs) : 2 kHz -20 kHz
The common limits are between 20 Hz – 20 kHz because that’s the average human hearing range (some people, especially kids might hear up to 22 kHz). Contrary to common belief the human ear does not perceive sound in a linear fashion and it’s tuned up to hear the middle frequencies better and gradually becomes more linear as volume increases (the standard is +85 dB SPL, mixing and mastering at this volume is considered best, but also you should never spend more than 4-6 hours/day at that level).
Amplitude is commonly known as Volume and is measured in decibels (dB). In mixing the amplitude represents a logarithmic change in volume from a reference point (eg. +1 dB will increase the multiply of the current volume by 10, while -1 dB will divide it by 10). There is also the SPL (Sound Pressure Level), it’s measured in dB and represents the actual volume you hear from your speakers/monitors, a value of 0 dB SPL represents the standard threshold of human hearing at 1 kHz (20 µPa RMS).