National Aeronautics and Space Administration

Level

2

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: 810-1000L
visiona

NASA’s Danielle Koch is wired for sound – and 

finding ways to make things quieter.

No matter where she is, Danielle listens for 

the sounds that surround her. She might hear 

a gentle breeze at the top of a mountain. She 

might hear the roar of an airliner’s jet engines 

during takeoff from an airport. Sounds 

intrigue her.

What do you hear right now? Is the room 

quiet, or noisy? Are you surprised by any of the 

sounds you hear? Whether you live in the city, 

suburbs, or out in the country, sounds of all 

kinds surround you too.

People react differently to different sounds. 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. Others consider 

jet engine noise to be a nuisance. They want it to 

go away, or at least be quieter.

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 

to do the job.

She calls her work “an engineering journey.” 

She has gone from the top of a mountain range 

in rural Oregon, to sitting on soggy wet soil 

surrounded by tall grass reeds, to a dome-shaped 

NASA sound laboratory in Ohio that looks 

like a futuristic igloo with a big door.

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, making it easier for sound 

researchers to do their work.
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So, how do you make a jet engine quieter? It 

has taken many years to find out, but there are 

solutions that work.

During Danielle’s search for ways to reduce 

engine noise, she realized that nature was full of 

possible solutions. Strolling deep in the forest, 

for example, she could easily hear the wind 

blowing through the trees.

Danielle wondered what it was in nature that 

helped her hear quieter sounds and if she could 

use those ideas to make airplanes engines 

less noisy. 

One example of something from nature she 

thought would work was honeycomb. The 

six-sided structure made popular by honeybees 

is strong and light weight. 

Danielle and her colleagues studied 

honeycombs and found they work quite well as 

noise insulators. After much testing, they came 

up with a way to put a layer of honeycomb 

material inside a jet engine.

This soundsuppressing layer is 

called an acoustic 

liner. It surrounds 

the noisy rotating 

machinery that is 

inside a jet engine. 

The layer makes 

things quieter for people on the ground as well 

as passengers on the airplane.

But the honeycomb material is just one 

idea that works. Danielle is confident other 

solutions will be found. She believes it is 

possible to create acoustic liners that will work 

even better than using honeycomb.

To do this, Danielle is again looking for ideas 

from nature. This time she’s thinking about 

the tall grass reeds that grow in wetlands. 

Experiments have shown the reeds are good at 

absorbing sound.

The problem is reeds are made of grass. They 

would not last long inside the superhot insides 
of a jet engine. But maybe they can create a 

new material that would act like grass reeds but 

would not burn up.

She is not giving up though. Trying new 

things, even when success is not guaranteed, 

is an important part of Danielle’s job as an 

acoustic engineer. Her job requires her to 

be a combination of a scientist, inventor, and 

problem solver. She must be willing to accept 

failure, too.

When things are not working as hoped, 

Danielle takes inspiration from the famous pilot 

Amelia Earhart. 

Amelia often tried risky new things during 

the early days of aviation. But that did not 

stop her. Amelia 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 wind up at NASA? 

Her journey started when she was young and 

discovered she enjoyed math and science. She 

wanted to know how things worked. She stayed 

in school, went to college, and studied hard to 

earn a degree in engineering.

Now Danielle gets to do what she loves every 

day. She thinks it is important to tell others 

about her passion, so she spends some of her 

time talking to younger students.

She hopes students will realize how rewarding 

a career as an engineer can be. If you have an 

interest in how things work and study hard, 

perhaps you will become an engineer and come 

up with a whole new way to make airplane 

engines quieter.

NP-2024-01-3215-HQ

National Aeronautics and Space Administration

Headquarters

300 E. Street, SW

Washington, DC 20546

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