Johns Hopkins University students faced a real-life challenge: Stop the screech of an ordinary leaf blower. The students succeeded. A Stanley Black & Decker version of their college engineering project could soon appear in stores.
Four budding engineers—Leen Alfaoury, Michael Chacon, Madison Morrison, and Andrew Palacio—focused on dampening the din of electric or battery-powered leaf blowers. Obviously, they still wanted full blasting power so gardeners and yard workers everywhere could push leaves and debris out of sight.
The lessen-the-noise task might sound simple. But “the sound that comes out of this leaf blower is very complicated,” says Palacio. He adds that blower noise “contains a lot of different frequencies.” He compares those sounds to the different “notes on a piano.”
Leaf blower sounds are complex, but imagine how complex the ear is! God designed the hearing of most living creatures to detect all those various notes—and to find some more pleasing than others.
The team analyzed the parts of a basic leaf blower and studied each sound. Since perfect silence is impossible (for now!), they decided to cut only the most shrill machine noises. So they examined why the machine made each different sound.
Students spent months brainstorming and experimenting. They nixed more than 40 options before deciding on a fairly simple attachment for the end of the blower nozzle. The piece works similarly to a car muffler or a gun silencer.
“Our product takes in a full blow of air and separates it,” says team member Leen Alfaoury. “Some of that air comes out as it is, and part of it comes out shifted.” She says dividing the air into two sections results in less noise.
Team member Michael Chacon says, “It ultimately dampens the sound as it leaves, but it keeps all that force, which is the beauty of it.”
The team’s design made a less obnoxious leaf blower. The sharpest frequencies are about 94% quieter, making the machine 37% quieter overall.
“It’s the difference between hearing a high-pitched whistle and hearing what you might think of as wind noise,” says Morrison.
Alfaoury describes the redesigned sound as “muffled.” She says, “The noise is deeper. It is not screechy.”
Stanley Black & Decker officials are eager to start manufacturing and selling the blower attachment. “It’s not just some cool theoretical thing,” says company strategy director Nate Greene. “This is a really rare and dramatic level of success.”
The student team expects their invention could soon help quiet other screeching appliances.
We’re looking at you, blow-dryer.
Why? God makes some people especially good at problem-solving. The ability to analyze a problem and find creative solutions helps others in myriad ways.
