Sound and Hearing

Properties of Sound

100

How is sound made?

When energy is applied to an object, it causes it to vibrate, which creates sound waves.

200

How do we measure how loud a sound is?

We use a sound meter to measure the loudness of sound using the unit of decibels.

300

What medium is the BEST sound conductor? Why?

Solid is the best sound conductor because it contains particles that are close together, which makes it faster for sound vibrations to travel from particle to particle.

400

If Mrs. Chambers stood in the middle of the classroom and spoke, why is it that everybody can hear her no matter where they are sitting in the classroom?

...because sound waves travel in ALL directions.

500

What does frequency mean? How is it measured?

Frequency is how fast a sound wave vibrates. It is measured by counting the number of vibrations per second in Hertz (Hz).

Parts of the Ear

100

The outer part of the ear that collects sound waves.

Pinna

200

This part of the middle ear has a thin skin that vibrates when sound reaches it.

Eardrum

300

This part of the middle ear is filled with liquid and hairs that move when sound waves reach it.

Cochlea

400

These are the tiniest bones in the human body. What is the group called? Name these bones in the correct order.

Ossicles (Hammer, Anvil, Stirrup)

500

This part of the ear carries sound signals to the brain.

Auditory Nerve

Volume and Pitch

100

What is the difference between volume and pitch?

Volume is how LOUD and SOFT a sound is. Pitch is how HIGH and LOW a sound is.

200

If you tap a glass of water with a pencil. Which glass would make a HIGHER pitch sound? The glass with the most amount of water, or the glass with the least amount of water?

The less water in a glass, the higher pitch sound it will make. More water = lower pitch sound.

300

Name 2 ways you can make a LOW pitch sound on a string instrument.

Pluck a thick string. Pluck a shorter string. Pluck a tighter string.

400

Tom and Wendy both had flutes. When they blew into their flutes, the sound made by Tom was louder. Why would this happen?

Tom must have blown harder into his flute than Wendy.

500

What happens to a sound waves frequency as pitch gets higher and higher?

The higher the pitch gets, the faster the sound waves frequency gets.

Amplifying & Muffling sound

100

What does it mean to amplify sound? Name one way you can amplify sound. (besides turning up the volume)

Amplify means to make a sound LOUDER. You can do this by moving closer to the sound, surround the sound waves with "walls" to help direct sound in one direction (cupping your hands to your mouth, putting sound into a bowl).

200

What does it mean to muffle sound? Name one way to muffle sound.

To muffle sound means to make sound quieter/softer. You can do this by moving farther away from the sound, and covering the sound with a soft material that can ABSORB sound waves, wear earmuffs/plugs.

300

Keeping in mind what medium is the BEST sound conductor. Which material would you use to help amplify sound? Why? styrofoam, sand, oil, wood

Wood would amplify sound the best because compared to the other materials, it is the most solid. Solids are better conductors of sound than liquids and anything with air in it.

400

Keeping in mind what you know about what medium is the WORST sound conductor, what material would you choose to sound proof your room? Why? metal, fabric, wood, styrofoam?

Styrofoam would be the best to sound proof your room because it has a lot of air pockets. Air is the worst sound conductor.

500

Mikes alarm clock was too loud in the mornings! What can Mike do to help soften the sound of his alarm clock?

Put his alarm clock on a pillow (filled with cotton). Move his alarm clock farther away from his head. Wrap his alarm clock in a blanket.

Miscellaneous

100

What happens to the sound when you touch the tip of a ringing tuning fork? Why?

The ringing sound will stop because when you touch the tip it will stop the vibrations. No vibrations = no more sound.

200

How can you protect your ears from noise pollution that could hurt your sense of hearing? List 2 different ways.

Wear ear protection (plugs/muffs). Don't listen to loud sounds for long periods of time. Turn down the volume. Try to stay far away from loud sounds.

300

How can we know if a sound is too loud and will cause permanent damage to your hearing?

We can measure it using a sound meter in decibels. If it is over 100 decibels, it is in the "danger" zone and will cause hearing loss.

400

Why would some sounds be considered pleasant?

Sounds can be considered pleasant if they are soft and smooth sounding. These sounds can make people feel relaxed, calm, happy, or being soothing to the ear.

500

Pick one animal and describe how its hearing is different from human hearing. Explain.

Elephants can hear really LOW pitch sounds that vibrate at a very LOW frequency (slow) that humans are unable to hear. Elephants also hear with 3 parts of their body: ears, trunk, and bottoms of their feet. Elephants can hear from longer distances away than humans can. Dogs can hear really HIGH pitch sounds that vibrate at a very HIGH frequency (fast) that humans are unable to hear. Dogs can also move their ears in many directions to help collect sound waves. Dogs can hear from longer distances away than humans can. Bats hear using echolocation. They make high pitch sounds that send out sound wave vibrations. These vibrations bounce off of insects or objects and back towards themselves. When they feel their vibrations return to them, they now know how far away or where their prey is located.