Science Fair Demo Ideas?

Herb Singleton · science forum beginner Joined: 04 May 2005 Posts: 46

Hey All,

The Boston Chapter of the ASA was asked if members were interested in
doing an acoustics demonstration for the Massachusetts State Science
Fair in May. Several of us are interested, but we're having a problem
coming up with an interesting demo that doesn't require a lot of prep
time given that we're all busy.

Anyone have any ideas? I'm hoping for something better then setting up a
spectrum analyzer and telling people "here, look at your vocal
spectrum."

(BTW, if anyone is interested in participating, contact Rose Mary Su at
Acentech rsu at acentech.com )

Herb

Don Pearce · science forum beginner Joined: 16 May 2005 Posts: 19

On Mon, 24 Apr 2006 14:38:16 -0400, Herb Singleton
<usenet3@cross-spectrum.com> wrote:

GregS · science forum beginner Joined: 30 Jun 2005 Posts: 47

In article <444d1e98.818779843@text.usenet.plus.net>, donald@pearce.uk.com (Don Pearce) wrote:

Repeating Rifle · science forum Guru Wannabe Joined: 25 Mar 2005 Posts: 205

On 4/24/06 11:38 AM, in article
usenet3-E2F81B.14381624042006@news.giganews.com, "Herb Singleton"
<usenet3@cross-spectrum.com> wrote:

Chris Notton · science forum beginner Joined: 05 Apr 2006 Posts: 5

In article <usenet3-E2F81B.14381624042006@news.giganews.com>, usenet3
@cross-spectrum.com says...

Herb Singleton · science forum beginner Joined: 04 May 2005 Posts: 46

Thanks everyone for the ideas.

I'm leaning toward the headphones demo - not a lot of equipment, and now
that I think of it, there were lots of headphone experiments that I
carried out in college that might be interesting.

Herb

TheGhost · science forum addict Joined: 09 Aug 2005 Posts: 85

Herb Singleton <usenet3@cross-spectrum.com> wrote in news:usenet3-
79C49E.19574026042006@news.giganews.com:

Florida Dave · science forum beginner Joined: 14 Nov 2005 Posts: 3

Herb,

How about a demonstration box that shows "insulation is not a sound
barrier"?
I made one many years ago, but no longer have it. It was a 1'x1'x1'
cube of 3/4" plywood. The top and sides were 3/4" were one piece. the
bottom (base) had a drycell battery and an doorbell about 2.5" dia. the
type with the clapper that banged on the side of it. I made up some
smaller parts same shape as the top and side part, but smaller so the
plywood top/side part could be put on top of them. One part was
fiberglass duct board (without foil), another was open cell foam. You
could also make one of mineral fiber acoustical tile or other
materials. Be creative. Changing out the different top/side components
while the bell is ringing gives a good demonstration of how mass is
important for noise reduction. Also there is a noticeable difference
wtih the plywood cover (with and without fiberglass inside.) Fairly
simple and inexpensive You could make a series of boxes, each with a
diffferent cover. And switch them off and on to demonstrate the
difference. You could set up a SLM and show the spectrum of each in
real time, or use a mike through as sound card and display on a laptop
screen.
You do want a seal on the bottom edged of the plywood box cover to
reduce crack leakage. Thin closed cell weather stripping works okay.

Just a suggestion.

Dave Fagen

Eric Rosenberg · science forum beginner Joined: 27 Apr 2006 Posts: 1

Nice little demo all packaged and ready to go re active noise control
from Virginia Tech:

http://www.val.me.vt.edu/Experiment/experiments.html

Eric

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