UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
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?
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 whatnot 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.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use