Fast and Easy Science Fair Projects: The Sound of Time

This is my 22nd hub on Fast and Fair Science Fair Projects. I'm sure you'll enjoy reading and trying out this one too! Good luck!

Amplifying Sound

Purpose: Sound is sometimes faint and hard to hear, how can it be amplified to improve hearing?

Overview: Sound waves traveling through the air can be gathered to make them louder. They can also be directed (focused) in one direction to make them louder. Have you ever seen a band shell behind a large orchestra playing outside?

     One way that sound is directed is by using a megaphone. A megaphone is a horn-shaped device used to increase the sound of a person's voice. Cheerleaders at a football game or the life-guard at a beach often use megaphones. Early record players, made before the invention of electronic amplifiers, used such horns to make the music louder for listeners.

     A megaphone works in reverse, too. It can gather sound and allow a person to hear weaker sounds better. Think about the shape of the outer ear which is responsible for gathering sound. At a football game on television, you might notice a technician standing on the side-lines holding a large curved dish? The parabolic dish has a microphone attached to pick up what the players are saying.

Hypothesis: Hypothesize that by using a paper megaphone at the source and one at your ear, you will be able to hear a sound louder than one that, without these devises, you are able to hear not at all or just barely.

You need:

• 2 standard-size sheets of construction paper
• Adhesive tape
• A clock that "ticks" or watch with an alarm
• Modeling clay
• Outdoor picnic table or chair
• A friend

Procedure: Roll a piece of paper into the shape of a horn and use adhesive tape to keep it in place. Make another horn so you have two of them.

     On a quiet, calm day, go outside and find a place (table, bench, stoop) to mount your sound source. You will need a clock that has an audible "tick" or a watch with an alarm, and some modeling clay in order to stand the watch on its side.

     Make sure the clock is ticking or turn the watch alarm on so that it produces beeping sound. Move away as far as you can from the clock or watch until you can just barely hear the sound. Then stop and hold one of the horns in your ear. Can you hear the sound any better?

     Now have a friend hold the other horn in front of the clock or the watch with the large end towards you. Does the beeping get even louder? The source of the sound is Constant; our Variables are two megaphone devices.

Note: If you do this experiment on a windy day ot could affect your results. When doing science projects, it's important to control all the variables, which means keep all the things constant, that is, of the wind speed and direction are the same when you listen with or without the horn, maybe the results of the experiment can be trusted. But if the wind is gusting ot swirling, it will very likely change the results.

Results and Conclusion: Write down the results of your experiment. Come to a conclusion as to whether or not your hypothesis was correct.

Something more: Does frequency (cycles per second) have an effect on the ability of the megaphones to amplify a sound? Use a music-instrument keyboard and compare the low note to the high note, both with and without the aid of megaphones.

     Thanks for reading this one! Hope you liked it! If you want more on Fast and Easy Science Fair Projects, you can try my other Hubs relating to the topic. Here are five of my latest Hubs on Fast and Easy Science Fair Projects for you: