Sound is a traveling longitudinal wave which is an oscillation of pressure. Humans perceive frequency of sound waves as pitch. Each musical note corresponds to a particular frequency which can be measured in hertz. An infant's ear is able to perceive frequencies ranging from 20 Hz to 20,000 Hz; the average adult human can hear sounds between 20 Hz and 16,000 Hz.The range of ultrasound, high-intensity infrasound and other physical vibrations such as molecular vibrationsextends into the megahertz range and well beyond.

The video for ‘Iron Heart’ shows our intrepid jungle protagonist running through the streets of Cardiff after being startled by a freaky looking child on public transport. Netsky, real name Boris Daenen, then becomes stuck in a time loop while an orchestra of extras play a game of Face-Swap with our leading hero.

Probably goes to show, he should never have taken the bus.