If you haven't used custom in ear monitors before don't worry, like everyone else, after your first few days of figuring out how to get them in and out you'll be an expert on the topic of custom in ear monitors and you will never want to go back to earphones, headphones or stage wedges again!
Despite custom in ear monitors being the main choice for professional musicians due to them being the most discreet, comfortable, customisable and offer the best isolation as well as stunning audio reproduction there has been some negative research into the occlusion effect and pneumatic air pressure causing ear fatigue and potentially hearing loss
So this is where the fun begins... there are now many different types of technologies from many custom IEM companies to combat this occlusion & pneumatic pressure buildup within your ear when using custom or very well fitted earphones.
Rather than over complicating the situation we decided to let the pressure build up work to our favour with proportional control. The centrifugal governor! It was invented in 1788 by James Watt to control his steam engine where it regulates the admission of steam into the cylinder(s). Its widest use was on steam engines during the Steam Age in the 19th century. As this technology has British written all over it with James Watt being the original inventor and HW Audio being a London based Custom IEM company, we had no choice but to call it.