7 TECHNOLOGIES THAT WILL MAKE THE FUTURE QUIET

7 Technologies That Will Make The Future Quiet
By Resonics, 24 June 2016.

The world is a noisy place.

So noisy, in fact, that scientists believe that there is no place left on earth that is untouched by man-made noise.

You might think that the North Pole might be a candidate for a bit of peace and quiet, yet even commercial airlines fly over the Arctic Circle between North America and Europe.

You literally cannot escape noise in the modern world.

So will there be any respite? At the same time that man-made noise pollution is wreaking havoc on the world around us, scientists are also working hard to create quieter everyday objects - from cars to kettles - with successful results.

Here are seven reasons why the future might be quieter than you think:

1. Less Roar From Aeroplanes

For the aerophobic of us (that means fear of flying, by the way) the slightest creak of whir heard while flying can be enough to induce all-out anxiety. Fortunately, aero engineers are working hard to make planes not only quieter for passengers, but for the rest of us on the ground, too.

Modern aeroplanes use a honeycomb structure to support the floor and ceiling of cabins. Unfortunately, this structure is an effective transmitter of sound waves - resulting in those off-putting mechanical noises you hear while in your seat.

To combat this noise scientists from North Carolina have created a negative density insulator made from latex, which when wrapped around the honeycomb directs noise away from the structure - keeping those whirrs and creaks out of the cabin.

Outside of the cabin, aeroplane engines are actually the quietest they have ever been. This is because planes are now being fitted with engines with high bypass ratios. “The bypass ratio is the proportion of the air which enters the engine inlet but bypasses the turbojet and exits at low speed, in comparison to the hot, high-speed jet coming from the engine core“. The greater the bypass ratio, the more air that avoids the turbojet and leaves the engine at a lower speed and volume.

2. Taking The Din Out Of Domestic Appliances

Domestic kitchens and laundries stand to be a whole lot quieter thanks to the creation and implementation of acoustic metamaterials (basically materials with properties found nowhere in nature).

Swiss scientists have developed a metamaterial that combines phononic crystals with tiny electrically charged disks that make the material adaptive. The composition of the material is able to be changed on demand thanks to the adaptive crystal structure.

This allows materials to be manipulated to remove physical connections and prevent vibrations in objects. In short - quieter washing machines and kettles.

3. Windows For A Good Night’s Sleep

If you live near a main road and traffic noise keeps you awake at night, this one’s for you. Korean scientists have developed a window that could give you that good night’s sleep you have been waiting for.

The window, made by scientists from Mokpo National Maritime Museum, can separate air from sound, and then block sound waves.

By combining negative density materials and resonance chambers that counteract the movement of sound, the window allows the passage of air while effectively blocking sound. Sound confusing? The above video might help explain.

4. Block Pesky Neighbours With Simple Panels

Noisy neighbours are one of the bug bears of modern life. The UK alone received over 400,00 noise complaints from neighbours in one year alone. While modern construction methods usually use some form or another of insulation between walls, the level of soundproofing offered by standard insulation is usually not enough to keep out a particularly noisy neighbour.

Thankfully Hong Kong researchers have created metamaterial no thicker than a ceramic tile, which can block noise across a wide frequency spectrum - meaning both low and high pitched sounds.

By combining latex and small plastic buttons tuned to resonate at different frequencies and then stacking these alternating membranes on top of each other, researchers have been able to create a broad-spectrum thin panel that could block out pesky noise from your neighbour’s man cave parties.

5. Whisper Quiet Cars

As better fuel efficiency becomes one of the rubber stamps of a good car, electric engines are becoming more sought after by drivers. One of the many overlooked benefits of an electric car is just how much quieter the engines are than normal cars - so much so that there are even concerns pedestrians are at risk of not hearing oncoming electric vehicles.

Holger Schulze, a musicology professor, told The Atlantic that if electric cars become widely adopted, then “the whole soundscape of our cities would change rapidly.”

6. Quieter Tarmac

Below the car’s wheels, there are even efforts to create quieter road themselves.

As The Atlantic has reported, ”Arizona, California, and other states have begun experimenting with something called quiet pavement, a rubberized asphalt or smooth concrete mix designed to lessen sound. In Phoenix, it cut traffic noise by 6 to 12 decibels, according to Robert Bernhard, the vice president for research at the University of Notre Dame.”

7. Mimicking Owls For Quieter Energy

Renewable energy accounts for only a fraction of the world’s energy sources; oil and coal still very much reign supreme. One reason that wind energy, being just one form of renewable energy, is so slow growing, is the concern over the noise they generate.

Yet, drawing inspiration from owls, wind turbines in particular are likely to be quieter thanks to a new material, which the University Of Cambridge describes as one “which mimics the wing structure of owls, could help make wind turbines, computer fans and even planes much quieter. Early wind tunnel tests of the coating have shown a substantial reduction in noise without any noticeable effect on aerodynamics.”

References:

1. Zigoneanu, Lucian, Bogdan-Ioan Popa, and Steven A. Cummer. ‘Three-Dimensional Broadband Omnidirectional Acoustic Ground Cloak’. Nature Materials 13.4 (2014): 352-355. Web. 30 Oct. 2015.

2. Rathi, Akshat. ‘This New Man-Made Material Could Get Rid Of That Horrible Airplane Noise’. Quartz. N.p., 2015. Web. 30 Oct. 2015.

3. New Scientist. ‘Latex Could Silence Noisy Neighbours’. N.p., 2015. Web. 30 Oct. 2015.

4. MIT Technology Review. ‘Redesigned Window Stops Sound But Not Air, Say Materials Scientists | MIT Technology Review’. N.p., 2013. Web. 30 Oct. 2015.

[Source: Resonics. Edited.]