Transcript for NASA Connect - Quieting The Skies

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[RJ:] What is that that noise?

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[RJ:] Watch out.

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[RJ:] Hi Van hey, hey.

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Hey I got to ask you question.

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What was all that about out there?

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[Van Hughes:] Well, Mr. Murphy
seems to think there are

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[inaudible] for the NASA Connect
class party was disturbing his nap

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[ Laughter ]

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I don't even see how
he could hear as much

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as there are noises outside.

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[RJ:] I know it's nearly when he
was talking to me I couldn't hear

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because of the plane
that was passing by.

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[Van Hughes:] We can
hardly even hear ourselves

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because of the planes around here.

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Let me introduce you the band.

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[RJ:] Oh great.

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[Van Hughes:] We have our
Van Huber on the bass guitar,

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Nick Brian Lara on the drums and

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[inaudible] on the keyboard, so
you are ready to hear us all.

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[RJ:] No, I don't think so guys.

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You are giving a little
visit you just have

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from Murphy don't you think
you might need to think

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about reducing the noise level
instead of practicing right now.

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[Van Hughes:] No we can
just close the garage door.

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[RJ:] Oh yeah Van I am
sure that would help,

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but you know somehow I think if
you have little more knowledge

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about the science, behind sound
and some properties, that you

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and your band might be all reduce
your noise level just a little

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bit further.

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As a fact, I know.

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I have got some friends
at NASA Langley

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who are studying noise abatement
that is how do you eliminate

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or reduce noise maybe they could
give us some insights as to how

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to stop disturbing poor Mr. Murphy.

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[Van Hughes:] Hey guys, the
children's museum of Virginia

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and Portsmouth have
some information

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about sounds it's not
too far from here.

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[RJ:] Hey, that's great idea.

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You know I think that be
a great place to start.

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So Van, why don't you and
the band kind of pack up,

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head on over to the museum, and
see what you can learn about sound.

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Meanwhile I will head on over

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to NASA contact some
acoustical researchers

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at NASA Langley in
Hampton Virginia.

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And see what I can learn
about noise control.

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And gang, you are invited
to Lang NASA you are part

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of the sound team.

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So as we do along we want
you to take some sound notes

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as we interview each
of our program guests.

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[RJ:] And as we go through the
show, you will be challenged

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to analyze data from an experiment
about sound that students at

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[inaudible] Middle School

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in Norfolk Virginia
performed for NASA.

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[RJ:] And with the help of
our Program Partner the FAA,

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students from Lexington
Massachusetts will also join us

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with some of the tech talk about
the fly in the skies website.

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[RJ:] And speaking of the website,

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when you see this sign
that's include to check

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out the cool NASA Connect
website for further information

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and activities related
to today's topic.

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[RJ:] And as we go along in
this program I like you to be,

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think about some questions
that you can phone or email

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into our researches
during today's program.

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Now then Nick, how about a
little drums more please.

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Ready gang, let's
shake revel and roll.

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[Van Hughes:] All right, I am
here at the Children's Museum

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of Virginia located in
Portsmouth Virginia.

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And this is Leslie

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[inaudible], the Museum's Curator.

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Hi Leslie!

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[Leslie:] Hi Van.

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I understand you want
to learn about sounds.

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[Van Hughes:] Yeah, I want to
learn about how sound works

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and especially how sound travels.

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[Leslie]: Well, let's have a
look at some of our exhibits

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and get the answers
to those questions.

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[Van Hughes:] Okay.

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[Leslie:] The Children's
Museum of Virginia is a place

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where kids can experience science
first hand here they can feel it,

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touch it, explore it, learn it.

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Let's first consider
how sound is produced.

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When sounds travel we actually are
hearing how the vibrations affect

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the air molecules.

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A way I can demonstrate,
this is with the slinky,

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Van hold the other end please.

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What we perceive as sound is
due to the alternate squeezing

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and stretching of
molecules through the air.

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This we refer to as sound waves.

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Sound waves travel through
the air at three hundred

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and forty-four meters per second.

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They travel slower than light.

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You can see this for yourself the
next time you see a thunder storm.

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You can work out how far
away the storm is from you

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by timing the interval between the
lightning and the clap of thunder.

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A storm is about one mile away
for every five seconds you count,

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or one kilometer for
every three seconds.

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Now that you know what sound
is and how fast it travels,

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let's do some testing.

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What do you notice?

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[Van Hughes:] The longer
the tube, lower the pitch.

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[Leslie:] Oh, sure!

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The air molecules in a long tube
vibrate more slowly producing

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a lower sound.

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Higher sounds vibrate more quickly.

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The difference in the number

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of vibrations per second,
we refer to is pitch.

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Want to try?

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Okay.

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[Van Hughes:] Cool.

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[Leslie:] We can also
use a recorder

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to demonstrate pitch you
use your fingers to lengthen

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and shorten the tube and
create higher and lower notes.

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[Van Hughes:] Well, that's great.

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But how do you make it louder.

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[Leslie:] Well, with
the recorder just simply

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by blowing more air into the tube.

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But there is another way
to make sounds louder

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and that's to focus sound.

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Let's go have a look.

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[Van Hughes:] Okay.

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[Leslie:] Here the parabolic dish
collects sound from a huge area

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and funnels it right to this point.

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If you are standing in just the
right place you can even hear

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a whisper.

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So, Van our Mr. Murphy is
only bothered by your sound.

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[Van Hughes:] Great, somebody
just asked me about Mr. Murphy,

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who asked that question.

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[Leslie:] Oh Van I would like to
introduce you to Dr. Linnet Roth,

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Doctor Roth is an Audiologist, she
specializes in hearing problems.

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[Van Hughes:] Oh!

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You mean like Mr. Murphy.

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Well, the question I have is
how come he singled out my band

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when there are so many other
noises in the neighborhood.

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[Leslie:] And might he Van like
many older people couldn't hear the

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higher frequency of noise that
came from other sound sources?

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[Van Hughes:] The
higher pitches, why?

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[Leslie:] Let me explain
how the ear works first.

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Sounds waves travel through the air

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and enter the ear canal
causing the ear drum to vibrate.

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The vibrations from the ear
drum cause with three bones

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in the middle ear to move.

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The last bone is called
the stirrup.

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The stirrup is attached
to a thin membrane.

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On the other side of this membrane
is fluid housed inside a curled

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snail shaped tool
called the cochlea?

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The vibrations from the stirrup
causes this membrane to flex

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which in turn sets
the fluid into motion.

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The moving fluid stipples thousands

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of delicate microscopic
hair-like cells called cilia.

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The cilia convert the vibration
in collective nerve impulses

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which the brain interprets
as sound.

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Higher frequencies
are heard by the cilia

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at the beginning of the cochlea.

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Lower frequencies
are heard at the end.

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The sound intensities degrade or if
it happens for up to a long period

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of time the cells will bay at
the beginning of the cochlea.

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Sound energy or intensity
is measured in decibels.

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Generally speaking the human
ear can comfortably hear

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between ten to eighty decibels.

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A quiet library typically
registered between forty

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to sixty decibels, while a
lot of rock concert registered

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above a hundred and ten decibels.

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[RJ:] Van its likely Mr. Murphy
has lost some of his ability

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to hear high frequencies.

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[Van Hughes:] So this explains why
Mr. Murphy singled out our band.

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[RJ:] Yes, Van but I am more
concerned about the ear safety

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of young people and in
particular The Noodles.

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Be careful for how loud
you practice your music,

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not for Mr. Murphy's comfort
but for your safety as well.

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[Van Hughes:] You bet.

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Dr. Roth, Mrs.

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[inaudible] things will let me
come over to the children's Museum

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of Virginia to learn about
sound and how the ear works.

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Okay. I now have a better
understanding of the science

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of sound and how people hear but
how do I will control the amount

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of sound coming from my
garage or to find the answer

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to that we are going to go to
back Shirley at NASA Langley

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to see what she is learning
about noise abatement.

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Perhaps she can pick up
a tip or two I can use.

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Meanwhile I will share this
information with my band

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and I will catch you later.

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[Shirley:] Oh!

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Great, you are just in time.

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Everybody let me introduce you
to Brenda Sullivan and Richard

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[inaudible].

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We are here at NASA
Langley in a building

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where they could do
acoustical research.

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Let's go here first to Rich.

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You are a Senior Research
Engineer, right?

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[Richard:] Correct.

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[Shirley:] Hi, and Brenda get
this name wrong Brenda you are a

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Psycho Acoustician.

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Now can you correct my wording

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and then tell me little
bit about what that is?

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[Brenda:] I'm the
Psycho Acoustician.

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Psycho acoustician is
somebody who designs, conducts

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and analyzes tests to study
the psychological affects

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of noise on people.

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[Shirley:] Oh!

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Psychological affects so
that's kind of interesting.

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And Rich how about
you, can you describe

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for us just what exactly is
a Senior Research Engineer?

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[Richard:] Well Shirley, there is
lot of noise research that goes

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on here relating to
Air Craft noise.

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And I work with researches both
here and at NASA Glen in Ohio

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and NASA Engine California
to come up with ways

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to reduce the noise
that Air Craft make.

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The word acoustics means the
scientific study of sound

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and how the qualities
of space affect sound

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to transmit were recorded.

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Why don't we begin with the
research that Brenda's told?

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Brenda why don't you
introduce Shirley

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to your fellow sound researchers?

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[Brenda:] Certainly
Shirley, meet Fred the Head.

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[Shirley:] This is Fred.

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[Brenda:] This is Fred, Fred
and his friend Norm here,

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are essentially my research.

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[RJ:] Testing the noise start

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with deciding what
aspect of noise to study.

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For instance, the sound in
a community near an Airport

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or the noise is inside
an actual airplane.

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So that's where Norm comes in.

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I take him up in the air
and inside the airplane

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so he can record the noises
as in there in flight.

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See he has got a microphone in
each ear that I try hard to see

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on Norm they are easier to
see on Fred let me show you.

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Yeah! He is alright.

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He is used to that
sort of treatment.

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See he has a mike in there its hard
to see, let me take his skull off.

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[Shirley:] Wow!

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[Brenda:] See he has a microphone

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in each ear anyway this little
microphones record the sound that's

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heard by each ear just as
you would hear yourself,

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I think this binaural recordings I
make with Norm and bring them back

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to the lab I can edit them on
the computer and play them back

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to the people who come in
direct to subject in my test.

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For instance, I can take some of
the turnings made by the propels

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of the plane and reduce them.

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And people can tell me if they
prefer to reduce directions

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and how much they prefer them.

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So we can predict their
reactions to future noises.

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[Shirley:] Oh!

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How interesting!

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[RJ:] Shirley if you
would like I can raise

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to show you NASA's
757 Research Air Craft

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and I can show you the physics
involved in producing the sound

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and how one goes about
controlling the sound.

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[Shirley:] Oh!

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Man there would be so cool.

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I know I am a viewer, I am sure
the viewers would be interested

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in seeing a real life NASA
Jumbo Jet Research Plane.

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[RJ:] So this is the NASA 757,

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in which we conduct
various types of research.

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NASA has a ten year goal to
reduce noise impact from aircrafts

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so the communities see
a one half of the noise

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that they heard in 1997.

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The amount of noise reduction
is similar to the difference

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between heavy traffic noise
and light traffic noise.

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The noise impact reduction
after it's led

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by NASA Langley Research
Center and is conducted

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in close partnership with NASA
Glen Research Center in Ohio

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and NASA Engine Research Center
in California along with help

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from Academia industry and the FAA.

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[RJ:] Wow, this aircraft is
huge, where do you begin to start

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to find the main resources of
noise that come from the aircraft.

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[RJ:] In some modern aircraft like
the 757 a lot of noise is generated

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from the air turbulence
created by the wind flaps,

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slaps and landing gear
slicing through the air.

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To control this type of
noise we use computers

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to create detailed models of the
air flow over these surfaces.

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Look for ways to smooth out the
flow and reduce the turbulence.

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Shirley, of course most

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of the noise is produced
by the jet engine.

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Modern jet engines have these
large fans that move large volumes

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of air through the engines.

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However the fan itself produces
what we will call fan terms.

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[RJ:] This type of noise is
reduced by creating the inlet

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and exhaust duct, with
special acoustic liners sort

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of like towels for office ceilings.

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[Richard:] And Shirley the
biggest noise problem we have is

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that of jet exhaust
noise and working with us

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in jet exhaust noise
is Martha Browne.

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Hi! Martha.

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[Martha:] Hi!

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Rich.

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[Shirley:] Hi!

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Martha.

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[Martha:] Hi!

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Shirley.

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[Richard:] Martha, Shirley
has a particular problem

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in noise abatement.

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Wonder if you could explain
to Martha, what it is?

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[Shirley:] Yeah!

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Thanks Rich.

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My problem is that I'm trying
to get some pointers on how

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to reduce noise, for my friend
Van and his band The Noodles.

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They were rehearsing in the garage.

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It seems that their rehearsals
are disturbing the neighbor

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as he's trying to take a nap.

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So we are trying to figure
out how to reduce the noise

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or the sound coming out of garage.

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Do you think you can help?

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[Martha:] I will be glad to help,
but first let me tell a little

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about myself and what I do at
NASA Langley I work as an engineer

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in the Jet Nose Laboratory.

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I study ways to change the air
coming out of the jet with the hope

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of reducing noise
created by this air.

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High speed air is needed to
move an airplane forward.

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I work with the team of engineers
to invent ways to change the speed

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of the air exceeding
the jet by jet mixing.

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[Shirley:] So just how do
you increase Jet mixing?

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[Martha:] Watch Shirley?

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We use non round shapes
like this rectangle nozzle,

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[00:14:36.249]
this elliptical nozzle and
also this quadric nozzle.

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[Shirley:] Oh, now this reminds
me of a flower with petals.

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[Martha:] I see what you mean
but in fact if they call lobes

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and also we may change the
round nozzle and how it looks

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by adding tabs at the
ends that you see here.

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[Shirley:] Oh no, these
tabs looks like short teeth,

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so what other ways do
you have to reduce noise.

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[Martha:] Well Shirley,
we use materials

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to line the inside of the nozzle.

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You see this is called a liner
and what it is used to do is

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to absorb the sound
before it exits nozzle.

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[Shirley:] Like a mop.

[00:15:15.459]
[Martha:] Yes!

[00:15:16.079]
[Shirley:] Okay, let's
go back to the end now.

[00:15:17.799]
What one point, might you make
Dr. Van help him with his problem?

[00:15:23.759]
[Martha:] I recommend
that he buys ceiling tiles

[00:15:26.479]
to line the ceiling of his garage.

[00:15:28.399]
[Shirley:] Okay.

[00:15:28.789]
[Richard:] And Shirley, he can
install carpet on the floor

[00:15:31.769]
and draperies on the windows
to help reduce the sound.

[00:15:34.189]
[Shirley:] Oh!

[00:15:34.629]
Rich and Martha that's
great sound advice

[00:15:37.389]
and I will share that
back with Van.

[00:15:39.419]
Thank you, so much.

[00:15:40.589]
[Richard:] You are very welcome.

[00:15:41.419]
[Shirley:] I and to the rest of
you gang I'm going to send you

[00:15:43.989]
to find Van and see what he
is up to meanwhile I am going

[00:15:46.619]
to head back to the NASA
Connect studio and get ready

[00:15:48.759]
for our special guest.

[00:15:49.889]
And if you haven't thought some
questions, think about some

[00:15:52.309]
because in a moment you will be
calling in with your questions.

[00:15:55.099]
I will see you back at the studio.

[00:15:58.779]
[Van Hughes:] Well while
I get things arranged

[00:16:00.379]
with my band The Noodles.

[00:16:01.649]
I am going to send you to

[00:16:02.589]
[inaudible] Middle School
in the Norfolk Virginia.

[00:16:04.519]
We will see students
from the classroom

[00:16:06.509]
of the science teacher, Miss Suzan

[00:16:08.319]
[inaudible] and Math
teacher Mr. Steven Davis.

[00:16:11.099]
They are conducting an experiment
examining the speed of sound,

[00:16:14.679]
follow a long and after that,
you can make your own analysis

[00:16:17.499]
and predictions based
upon their results.

[00:16:19.839]
So I will catch you all later.

[00:16:23.469]
[Students:] Hi, we
are students from

[00:16:25.699]
[inaudible] Middle School
in Norfolk Virginia.

[00:16:29.859]
NASA connect asked us to
investigate how sound waves travel

[00:16:34.499]
at different speeds
under various conditions.

[00:16:36.809]
In this project we will be
measuring the speed of sound

[00:16:40.789]
and calculating the percentage of
air with our science teacher Miss

[00:16:45.039]
[inaudible] and our Math and
Science Teacher Mr. David.

[00:16:48.859]
To prepare the experiment pour one
or two tablespoon of powdered sugar

[00:16:53.199]
onto the middle of four
sheets of tissue paper.

[00:16:56.229]
Pull up the corners
and tie it with string.

[00:16:59.269]
Make four bags for the experiment
and two additional bags in case

[00:17:03.159]
of accidental breakup.

[00:17:04.839]
Now we are ready to go.

[00:17:06.489]
First we record the wind
direction, weather conditions,

[00:17:09.949]
and outdoor temperature associates.

[00:17:12.489]
Next we mark the spot where the
sound engineer will hit the bags.

[00:17:16.839]
From this point we measure
out fifty meter intervals.

[00:17:20.579]
The linear speed engineer teams are
located at each of these intervals.

[00:17:25.319]
The sound assistants hold up
the bullets and board paper

[00:17:29.029]
to create a dark background
behind the sound engineer

[00:17:32.349]
which will help the speed
engineers to see the puff of smoke.

[00:17:36.459]
The sound engineer takes
one of the bags of powder

[00:17:39.309]
to the middle bottom of the pan.

[00:17:41.829]
When the sound person hits the two
pans together, bursting the bag

[00:17:45.509]
of powder the linear speed
engineers start their stop watches

[00:17:49.539]
at the first sign of smoke
and to stop them as soon

[00:17:53.039]
as they hear the sound.

[00:17:54.309]
Warning, be ready to use
a quick reaction time.

[00:17:57.959]
Ready, set go.

[00:18:00.899]
[00:18:02.209]
The experiment is performed
at least three times

[00:18:04.889]
to get a range of data.

[00:18:06.889]
Now we return to the
classroom to analyze data.

[00:18:11.039]
[RJ:] Mr. David, gives
us the formula

[00:18:12.729]
for determining the speed of sound?

[00:18:15.289]
Speed equals to distance
divided by time.

[00:18:18.289]
Using the data collected,
we calculate the speed

[00:18:21.349]
of the sound at each location.

[00:18:23.539]
We compare results
between the locations.

[00:18:26.209]
Mr. David asks what do
these numbers represent?

[00:18:30.499]
Next, each will calculate the
accepted value for the speed

[00:18:34.109]
of sound at the recorded
outside temperature.

[00:18:37.039]
After we have posted our
results, Mr. David asks us

[00:18:40.079]
to calculate the percentage
of error

[00:18:42.409]
in the experiment using the
following formula of amount

[00:18:45.339]
of air divided by the accepted
value times one hundred.

[00:18:50.159]
We have a good time applying
Math to solve the problem.

[00:18:53.619]
[00:18:55.379]
[Shirley:] Alright, welcome
to the NASA Connect studio,

[00:18:58.529]
now joining in the studio Richard

[00:19:00.939]
[inaudible] a Senior
Research Scientist

[00:19:02.359]
and we are also now joined by Denis

[00:19:04.489]
[inaudible] from NASA Glen
Research Center in Cleveland Ohio,

[00:19:07.499]
but before we talk
to our researchers,

[00:19:09.409]
let's give you a chance to do
some analyzing using the data

[00:19:12.609]
from your experiment you just saw.

[00:19:14.639]
After this segment, our two
researchers will be answering your

[00:19:17.589]
e-mail questions and
taking questions

[00:19:19.409]
from the viewing audience.

[00:19:21.059]
Okay, now look carefully at the
data and use the information

[00:19:24.339]
in the following diagram.

[00:19:25.759]
Work with your fellow students
to answer the questions

[00:19:28.279]
as well allowed by Richard

[00:19:29.879]
[inaudible].

[00:19:30.049]
[Richard:] As the distance
increase from fifty meters,

[00:19:35.269]
what happened in the meantime?

[00:19:37.979]
[00:20:14.099]
Use the formula, percent

[00:20:16.309]
of experimental error equals
calculated value minus accepted

[00:20:21.149]
value divided by the accepted
value times one hundred

[00:20:26.499]
to calculate the percentage
of air at fifty meters

[00:20:29.309]
and three hundred meters.

[00:20:31.259]
Why do you think they
are different?

[00:20:33.789]
[00:20:53.889]
The speed of sound is directly
proportional to air temperature.

[00:20:57.159]
Is the speed of sound
faster in summer or winter?

[00:21:01.169]
Why?

[00:21:02.539]
[00:21:32.619]
[Shirley:] Alright, we are
back and with me are Rich

[00:21:34.889]
[inaudible] and Denis

[00:21:35.339]
[inaudible] to answer your
questions but lets start things off

[00:21:38.049]
by asking Denis what is it Denis

[00:21:40.369]
that you actually do
there at NASA Glen?

[00:21:42.449]
[Denis:] I'll like to answer
that; however my name Denis

[00:21:44.509]
[inaudible] I'm the Chief
of the acoustics branch

[00:21:46.329]
of NASA's Glen Research Center.

[00:21:48.009]
It's located in Cleveland, Ohio.

[00:21:49.999]
Our contribution acquiring
the sky looks so waste

[00:21:52.479]
in making the engines quieter.

[00:21:54.509]
Our goal is to develop engine
noise reduction technology

[00:21:57.229]
without compromising
the engine performance

[00:21:59.479]
or the Air Craft safety.

[00:22:01.509]
Some members of our team
develop mathematical models deal

[00:22:04.389]
to predict the sound from the
engine while others test different

[00:22:07.699]
parts of the engine inside wind
tunnels and anti-clog chambers.

[00:22:10.959]
Our best noise reduction
concepts will eventually be tested

[00:22:13.719]
on engines to make sure we can
really make the Airplanes quieter.

[00:22:17.419]
[Shirley:] Yet a lot of good stuff

[00:22:18.989]
[inaudible] I could ask a lot of
questions about and I just might do

[00:22:22.179]
that Denis but I have
got some e-mail questions

[00:22:24.079]
that have come in
for both you guys.

[00:22:25.899]
So let me start with
an e-mail question.

[00:22:27.779]
The first question is, does the
shape of a plane affect the sound

[00:22:32.779]
and this is from Jonathan
in Virginia Beach.

[00:22:36.369]
[Richard:] Yeah, Shirley the shape

[00:22:38.359]
of the Airplane does change
the sound dramatically.

[00:22:41.089]
First as when Airplane coming in
for landing or taking-off the flaps

[00:22:45.639]
in the landing gear are deployed
in that case the flow is very dirty

[00:22:49.279]
and makes a lot more noise

[00:22:50.519]
than when those components
are stored away.

[00:22:54.879]
[Dennis:] Yes, and in
fact it's interesting

[00:22:56.309]
on the engine itself
you've noticed that some

[00:22:58.769]
of the older Aircraft have
smaller diameter engines

[00:23:01.959]
and the smaller diameter
actually passes a lot more flow

[00:23:04.619]
at a higher velocity and
this causes the jet noise

[00:23:06.999]
to be very loud.

[00:23:08.379]
We have a general rule formed
that we say that the velocity

[00:23:11.769]
of the exit of the velocity
raised is powered, is proportional

[00:23:15.399]
to the jet noise so
the newer Aircraft

[00:23:17.359]
that have larger diameter engines
actually end of being quiet.

[00:23:20.719]
[Shirley:] Alright
and let's go back to

[00:23:23.139]
[inaudible], how we answer this
alright but I am through about me

[00:23:24.939]
who flies not along these small
little of the compactor jumpers

[00:23:28.099]
or commuter planes compared
to your bigger 757's

[00:23:33.429]
and how's there a difference on
those size of engines and the noise

[00:23:39.319]
that they are generating?

[00:23:40.559]
[RJ:] Sure, those engines are some

[00:23:42.019]
of the newer engines we call
those higher by pass ratio engines

[00:23:45.229]
and so you got a lot of fog on
through that so lot of thrust

[00:23:47.649]
in that engine but it's
going at a lower velocity

[00:23:49.759]
so its a much quieter
engine than the older ones.

[00:23:52.229]
[Shirley:] Oh!

[00:23:52.839]
Okay.

[00:23:53.739]
[RJ:] In a lot of cases propeller
Airplanes are quieter too they are

[00:23:57.459]
quieter than the large jets on.

[00:23:59.349]
[Shirley:] I got a question
you keep talking about research

[00:24:02.589]
to reduce noise around
communities, what is the community

[00:24:06.749]
that you all are referring to here.

[00:24:09.719]
[RJ:] Generally we are
talking about that area

[00:24:11.259]
around the airport that's
affected by the operations

[00:24:13.969]
of the Airplanes taking off

[00:24:15.219]
and landing once the Airplane
climbs how about to as a cruise

[00:24:20.229]
out about to may be at 35,000
feet you don't really hear much

[00:24:23.829]
any more.

[00:24:24.619]
[Shirley:] Okay, alright, good.

[00:24:25.449]
Well I have got someone tell me,
we have got a caller out there

[00:24:28.349]
so let's go and take that caller.

[00:24:29.999]
Caller can I have your first
name please and your question.

[00:24:33.449]
[Boy:] My name is Timothy

[00:24:40.049]
and my question is how fast
does sound travel through water?

[00:24:48.719]
[Shirley:] Oh, okay, the
sound traveling through water

[00:24:52.779]
and is there a difference
between the speed

[00:24:54.479]
that sound travels
in air and water?

[00:24:57.449]
[RJ:] Yes, the speed travels
through water much more quickly

[00:24:59.849]
than that does in the air.

[00:25:01.179]
I can't recall the exact
number I think it's three

[00:25:04.489]
or four times faster in
water than it is in air.

[00:25:07.939]
[Shirley:] Okay, alright so we know
that it is going to travel faster

[00:25:11.329]
through water than in air
good question there Timothy

[00:25:15.059]
and we will take a final question.

[00:25:16.659]
I have here by e-mail very quickly.

[00:25:19.989]
Well know final advice what advice
would you Dennis give to viewers

[00:25:23.029]
about thinking about careers.

[00:25:24.309]
[Dennis:]

[00:25:24.679]
[inaudible] answered that my
part of game in the advise

[00:25:26.879]
to keep your options open
you can get into a lot

[00:25:29.369]
of different activities and
make sure you involved there

[00:25:31.289]
so often extracurricular
activities but also stay

[00:25:33.779]
with your math and science

[00:25:34.989]
and your English all the different
courses are very important.

[00:25:38.079]
[Shirley:] Alright
there you got it from us

[00:25:40.219]
and I see we are quickly
running out of time.

[00:25:42.439]
Thank you Dennis and
Rich and now students

[00:25:44.869]
from Jonas Clarke Middle School

[00:25:46.249]
in Lexington Massachusetts share
some technology notes that are sure

[00:25:49.849]
to shop in your investigation
on sound following this program.

[00:25:57.419]
[RJ:] One part of the website is
called the NASA sound machine.

[00:26:00.739]
We think you all learned about
the shapes and characteristics

[00:26:03.509]
of sound waves, how an Airplane
produces different kinds of noise

[00:26:07.379]
and what certain words would
sound like if you had severe

[00:26:10.029]
or partial hearing loss.

[00:26:11.609]
Another part of the NASA Connect
website features NASA researches

[00:26:15.509]
talking about their jobs.

[00:26:17.039]
It's called Career Corner.

[00:26:18.509]
There is also a fun quiz
that will test your knowledge

[00:26:21.149]
of sound and hearing.

[00:26:23.129]
[Shirley:] Hey, a big thanks now
to our Jonas Clarke Middle School

[00:26:26.659]
for that technology
T's and thank you

[00:26:28.979]
to all our program
guests and partners.

[00:26:32.359]
If you wish a video tape copy
of this NASA Connect show

[00:26:35.049]
and lesson plans then contact
CORE the NASA Central Operation

[00:26:38.819]
of Resources for Educators.

[00:26:41.889]
Well, gang that's it for
this season of NASA Connect

[00:26:44.509]
but join us again next season from
more in NASA Connect programs math,

[00:26:48.439]
science and researchers and of
course for more event and me.

[00:26:52.749]
I will be joining you from our
nation's capital Washington D.C.

[00:26:55.849]
as a special correspondent
to NASA Connect.

[00:26:58.489]
Now let's do a final
sound check on Van

[00:27:01.019]
as he professionally
records his song.

[00:27:04.449]
[Van Hughes:] Okay I think
we have something pretty good

[00:27:06.449]
for you Shirley, ready guys.

[00:27:08.999]
Hit it.

[00:27:09.369]