National Aeronautics and Space Administration

Level

3

Lexile Ranges

Level 1: Less than 810

Level 2: 810-1000L

Level 3: 1010-1200L

Level 4: 1210-1400L

Educational Product

Educators & Students Lexile Level: 1010-1200L
WORK HA

NASA’s Danielle Koch is wired for sound – and finding 

ways to make things quieter.

No matter where she is, Danielle is tuned in to the 

sounds that surround her. Whether that is from a gentle 

breeze at the top of a mountain or the roar of an airliner’s 

jet engines during takeoff from an airport, she has always 

been intrigued by the sounds she hears. 

Take a moment right now and just listen. What do you 

hear? Is the room quiet, or noisy? Are you noticing any 

sounds you would not normally hear unless you were 

listening for them, just like you are doing now? Whether 

you live in the city, suburbs, or out in the country, sounds 

of all kinds surround you.

What if you live near a big airport? If you love airplanes 

you may think the sound of a jumbo jet flying overhead 

or racing down a runway is music to your ears. But for 

most everyone else, that sound is considered noise 

pollution and they would like it to go away, or at least be 

quieted as much as possible.

As a researcher who works for NASA, that is what 

Danielle does. She leads a team of engineers who study 

ways to reduce engine noise by designing, building, and 

testing new parts that can be installed in an airplane’s 

engine.

She calls her work “an engineering journey,” and it’s a 

journey that has taken her from the top of a mountain 

range in rural Oregon, to sitting surrounded by tall 

wetland reeds, to conducting research at a NASA sound 

laboratory in Ohio that looks like a futuristic igloo with 

a big door.

That facility is officially known as the Aero-Acoustic 

Propulsion Laboratory. It is in Cleveland at a NASA 

research field center named for John Glenn, who in 1962 

became the first American to orbit Earth. 

The dome-shaped building is 65 feet high and 130 feet 

in diameter at its base. That is as tall as a six-story office 

building and just a little bit wider than the distance the 

Wright Brothers flew on their first history-making flight 

in 1903.

Inside, 17,000 custom-designed fiberglass wedges are 

mounted on the dome’s walls and floor. These wedges 

keep sounds from echoing in the dome, which allow 

researchers to more precisely study engine noise or 

whatever sound-making device is being tested at the time.

So, how do you make a jet engine quieter? Turns out 

there are several ways it can be done, but it took research 

over many years to come up with some ideas that would 
work. That work is not finished, either. Danielle and her 

team constantly look for new ways that work even better.

During Danielle’s search for ways to reduce engine noise, 

she realized that nature was full of possible solutions. She 

noticed that when out in nature, away from traffic and the 

louder noises so many of us typically hear every day, the 

sounds we hear change and are often quieter. Strolling 

deep in the forest, for example, wind blowing through the 

trees can easily be heard.

This gave Danielle the idea to take a close look at the 

different materials and structures found in nature to 

best understand which ones were best at absorbing 

noise. She hoped to adapt what she found to airplane 

engines.

One example of something from nature she thought 

would work was honeycomb. Humans have found ways 

to use the honeybee-invented structure made up of 

hexagonal (six-sided) sections for centuries because it is 

strong and light weight. 

Danielle and other researchers who have studied 

honeycombs found they also work quite well as 

noise insulators. After much testing and years of 

experimentation, they came up with a way to put a layer 

of honeycomb material inside a jet engine.

This layer is called an acoustic liner because it surrounds 

the loud rotating machinery inside a typical jet engine 

and absorbs the intense sound. This reduces the airplane’s 

noise level heard on the ground. It also makes the flight 

quieter for passengers inside the airplane.

Although these liners are effective at noise reduction 

and help the airlines comply with rules about how 

loud a jet engine can be, Danielle and her team are not 

satisfied. They believe 

it is possible to create 

acoustic liners that will 

work even better than 

using honeycomb.

To do this, Danielle is 

once again turning to 

nature for inspiration 

and her time among 

the tall grass reeds common in wetlands. Experiments 

have shown that bundles of reeds are good at absorbing 

sounds, but there is one big problem. Natural grass reeds 

are not durable enough to withstand the super-hot, 

high-pressure environment inside a jet engine. Danielle 

and her team are working to get the same effects as grass 

reeds, but with materials that can withstand the heat of 

an engine.

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She is not giving up though. Trying new things, even 

when success is not guaranteed, is an important part of 

being an aerospace engineer. It is a job that requires her to 

be part-scientist, part-inventor, and part-problem solver. 

Sometimes failure is an option.

When things are not working as hoped, Danielle takes 

inspiration from the famous pilot Amelia Earhart. 

Amelia often tried new things during the early days of 

aviation, many of them risky. She once wrote a letter 

to her husband, saying “Please know I am aware of the 

hazards. I want to do it because I want to do it. Women 

must try to do things as men have tried. When they fail, 

their failure must be a challenge to others.”

So, how did Danielle start her engineering journey? 

When she was younger, she enjoyed math and science 

and wanted to know how things worked. This led her to 

study fluid and thermal engineering sciences in college. 

Now, as a NASA engineer, she gets to do what she loves 

every day.

Danielle enjoys being an engineer, so much so that she 

shares her passion with others. She acts as a mentor 

helping students of all ages learn about engineering 

careers. She hopes students will realize how rewarding a 

career as an engineer can be. 

So, the next time a jet airplane flies overhead, and the 

noise does not interrupt your conversation, give a shout 

out to Danielle and her colleagues who have worked to 

keep things in the air as quiet as possible. And consider 

the possibility that one day you could be part of a team at 

NASA, working alongside Danielle hunting for the next 

big idea in noise abatement.

Educators! 

Guide/assessment files 

for this reader are at 

https://www.nasa.gov/

stem-content/

danielle-koch/

Another way NASA has reduced jet engine 

noise, which Danielle helped research, is seen 

on this Boeing 787. The saw-toothed cuts at 

the back of the engine change how the jet’s hot 

exhaust mixes with cold outside air. That makes 

the engine quieter.

Credits: The Boeing Company/Bob Ferguson