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For my 8th grade science fair project I am going
to run mice through mazes. To make it a little
more interesting I am going to put a pulsing
sound at the end to see if the mice can find it
any faster than without a sound. So I was
wondering if you had any research on the way mice
hear?
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Question Date: 2004-12-14 | | Answer 1:
Mouse ears work pretty much the same way our
ears do. However, they are able to hear
sounds that are so high the we can't hear
them. They can communicate with each other
with these "ultrasonic" sounds. They can
hear what we hear too, so they should be able to
hear your pulsing sound just fine. (By the way,
according to the US Centers for Disease Control,
Ultrasonic pest repellers don't work.)
To test your hypothesis that they find the goal
faster with a sound pulse, you will have to be
careful in how you design your experiment. For
example, let's say you have a maze and you test
your mice in it and find that it takes them 5
minutes to find the end. Each time they find the
end, you give them a treat. After 10 times, they
find the end in 30 seconds. Now you add the sound
and they find it in 15 seconds. Did the sound
help, or did they just keep learning?
Or let's say you test a new group of mice in
the same maze, using the sound cue, and they find
it in 3 minutes the first time. Did the sound
help, or did they smell the old food that was left
behind from earlier tests? Or did they
smell the trail of past mice?
Maybe you change the maze and add the
sound and they find the end in 3 minutes the first
time. Did the sound help, or was this an easier
maze?
One way to avoid these problems is to use
"randomization."If you have a few mice, you
flip a coin for each one to see whether it gets
the sound or not. Then you train them in a
random order (pull their number or name out of
a hat). Then the comparison between your tests is
fair.
This is not the only way to make a fair test,
but think carefully about your experiment before
you start, because you can't fix it
afterwards.
Have fun with your project. | | Answer 2:
Most of the research into mouse hearing is
overly technical or probably unrelated to your
project. (There's research about mouse ear
stem cells being used to help people with hearing
problems, research looking for genes related to
mouse hearing, and deafness in mice induced by
certain gene mutations).
You may already know that mice have more
acute hearing than we do. Since they're
nocturnal (active at night), and since
they spend so much time in tunnels and small
spaces, they use their hearing more than their
vision for many things. In fact, they are very
sensitive to motion up to 30-50 feet away, and
they detect this motion through hearing and
through their whiskers.
Mice can hear between sound wave frequencies
of 1,000 to 100,000 Hertz, but people can hear
frequencies between 20 and 20,000 Hertz. Hertz
is a measurement of frequency or what you and I
think of as pitch. This means that humans can hear
lower pitches (20 Hertz) than mice can (1,000
Hertz),but mice can hear much higher pitches than
we can (100,000 Hertz instead of only 20,000
Hertz).
You may be able to use this information about
sensing motion or pitch in your experiment
somehow. Good luck! | | Answer 3:
That sounds like a really interesting research
question for your project. I'm not an expert on
rodent hearing, but I can tell you a few things.
First, mice have big ears (for their body
size), so there's a good chance that hearing
is quite important to them. Second, I know that
scientists who do research on hearing problems use
mice as study organisms, so there's a good chance
your experiment will work just fine. As far as
how mice hear, I would suspect that they can hear
the same sound frequencies we can hear, plus they
can probably also hear some higher frequencies.
So if you pick a pulsing sound that you can hear,
I bet the mice will hear it just fine. I also have
two suggestions for your experimental design
(although perhaps you've already thought of these
things!).
First, sound waves and other kinds of waves
(like electromagnetic waves) can bend around
objects. This is why you can hear things you
can't see, such as if you and a friend were
standing with a tree between you -- you could
still talk to each other even though the tree was
blocking the most direct path between your mouth
and his ears. The amount that a wave will bend
like this depends on its wavelength -- long
wavelengths bend more.
This is why radio waves (long wavelength
electromagnetic waves) can bend around buildings
and mountains, but light waves (short wavelength
EM waves) cannot. So we get a radio signal when
standing behind a building, but we can't see
around the building. In the same way, long
wavelength sounds (deep sounds) will bend more
than short wavelength sounds (high-pitched
sounds). This is why it can sometimes be
harder to figure out where a deep bass sound is
coming from than where a high pitched sound is
coming from. So that's something you may want to
think about -- perhaps use a range of sound
frequencies to see if the mice are helped by some
but not others; or at least try to use a somewhat
high-pitched sound to make sure the mice can
actually find it.
Second, when you're running the mice in the
mazes, I would assume that you'll do some control
runs without the sound. When you do these
controls, you'll need to be sure that the
setup is exactly the same, just without the
sound. So all the same speakers and what not
should be in place, just not producing sound.
That way you'll be able to test just for the
effect of sound without your results being
confounded by the way the presence of the speaker
and the rest of your apparatus affect the mouse's
behavior (for example, if they like the way the
speakers smell or something). Click Here to return to the search form.
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