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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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[00:12:06.879]
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
[00:12:19.219]
between heavy traffic noise
and light traffic noise.
[00:12:22.859]
The noise impact reduction
after it's led
[00:12:24.719]
by NASA Langley Research
Center and is conducted
[00:12:27.579]
in close partnership with NASA
Glen Research Center in Ohio
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and NASA Engine Research Center
in California along with help
[00:12:35.139]
from Academia industry and the FAA.
[00:12:38.269]
[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.
[00:12:45.169]
[RJ:] In some modern aircraft like
the 757 a lot of noise is generated
[00:12:49.079]
from the air turbulence
created by the wind flaps,
[00:12:51.809]
slaps and landing gear
slicing through the air.
[00:12:55.489]
To control this type of
noise we use computers
[00:12:58.679]
to create detailed models of the
air flow over these surfaces.
[00:13:02.699]
Look for ways to smooth out the
flow and reduce the turbulence.
[00:13:05.959]
Shirley, of course most
[00:13:06.889]
of the noise is produced
by the jet engine.
[00:13:09.669]
Modern jet engines have these
large fans that move large volumes
[00:13:13.219]
of air through the engines.
[00:13:14.879]
However the fan itself produces
what we will call fan terms.
[00:13:18.319]
[RJ:] This type of noise is
reduced by creating the inlet
[00:13:20.549]
and exhaust duct, with
special acoustic liners sort
[00:13:23.759]
of like towels for office ceilings.
[00:13:26.679]
[Richard:] And Shirley the
biggest noise problem we have is
[00:13:28.689]
that of jet exhaust
noise and working with us
[00:13:31.499]
in jet exhaust noise
is Martha Browne.
[00:13:33.259]
Hi! Martha.
[00:13:33.959]
[Martha:] Hi!
[00:13:34.169]
Rich.
[00:13:34.709]
[Shirley:] Hi!
[00:13:35.089]
Martha.
[00:13:35.369]
[Martha:] Hi!
[00:13:35.719]
Shirley.
[00:13:36.949]
[Richard:] Martha, Shirley
has a particular problem
[00:13:39.189]
in noise abatement.
[00:13:40.449]
Wonder if you could explain
to Martha, what it is?
[00:13:42.259]
[Shirley:] Yeah!
[00:13:42.559]
Thanks Rich.
[00:13:43.409]
My problem is that I'm trying
to get some pointers on how
[00:13:46.679]
to reduce noise, for my friend
Van and his band The Noodles.
[00:13:50.289]
They were rehearsing in the garage.
[00:13:51.489]
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
[00:14:03.899]
about myself and what I do at
NASA Langley I work as an engineer
[00:14:07.449]
in the Jet Nose Laboratory.
[00:14:09.429]
I study ways to change the air
coming out of the jet with the hope
[00:14:12.839]
of reducing noise
created by this air.
[00:14:15.619]
High speed air is needed to
move an airplane forward.
[00:14:19.249]
I work with the team of engineers
to invent ways to change the speed
[00:14:23.259]
of the air exceeding
the jet by jet mixing.
[00:14:26.039]
[Shirley:] So just how do
you increase Jet mixing?
[00:14:28.839]
[Martha:] Watch Shirley?
[00:14:29.669]
We use non round shapes
like this rectangle nozzle,
[00:14:34.369]
[00:14:36.249]
this elliptical nozzle and
also this quadric nozzle.
[00:14:40.009]
[Shirley:] Oh, now this reminds
me of a flower with petals.
[00:14:43.479]
[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
[00:14:51.999]
by adding tabs at the
ends that you see here.
[00:14:54.449]
[Shirley:] Oh no, these
tabs looks like short teeth,
[00:14:57.719]
so what other ways do
you have to reduce noise.
[00:15:00.419]
[Martha:] Well Shirley,
we use materials
[00:15:02.009]
to line the inside of the nozzle.
[00:15:04.739]
[00:15:07.699]
You see this is called a liner
and what it is used to do is
[00:15:10.949]
to absorb the sound
before it exits nozzle.
[00:15:14.629]
[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]