SCIENCE ACE-SOUNDBy: Mark Soh 2A226

Agenda

Reason for doing sound Introduction to sound Terminology in sound Our ears and hearing aids Sound waves Decibels Sound in nature Echoes

Reason for doing sound

If you could remember I did light last term. I realized that light and sound was sort of a ‘package’ in life as they together are able to form the most amazing things such as television shows and music videos. So I decided to do this ace regarding sound.

Introduction to sound

Basically sound is what we hear around us. If I were to draw a map on how sound has been like since young…

Babies make A LOT of sound ( eg. Crying )

Children make considerably loud noise, especially in class, with no doubt is because they are talking

Then comes the teenagers. In this case you realize they stay cool in a corner. BUT the music they play on their iPods I deafening

As they turn into adults, they start to hate noise and prefer the peace in the hillside or something

As they turn into old people, the most commonly used phrase would be : What did you say?

This is our life with sound

Terminology in sound

Terminology would refer to the words used when referring to sound scientifically.

AMPLITUDE – It means how loud something is. Stronger sound waves (explained later) means louder sounds or greater amplitude. Amplitude also comes from the word ample which means plentiful (as said by dictionary.com)

Terminology in sound

FREQUENCY – Frequency means the number of vibrations a second that make up the sound. Take a bat squeak compared to a dog’s bark for example. The bat’s squeak is of a higher frequency than a dog’s bark because it’s sound produced is higher. This is measured in hertz (written Hz). Hence higher frequency makes more hertz.

Terminology in sound

TONE – This is a sound with one frequency. Hence in songs the tone varies. If it doesn’t, it would sound monotonous. This can be produced by hitting a tuning fork.

RESONANCE – This is when vibrations hit an object at a certain frequency. As the object vibrates more, the sound gets louder and louder.

Terminology in sound

HARMONICS – All sounds are made up of harmonics. As long as the harmonics are working on the same frequency, the sound produced would be nice to listen to. If it is still unclear, harmonics are the basis of all songs. Harmonics in songs are like the ‘timers’ in frequency, setting when the best time for a certain frequency to turn up. Hence it can be harmonious.

Our ears

Our ears consists of these parts: The ears itself Ear-drum Ear bone Oval Window The nerves that go from the ear to the

brain

Ear Canal

The external ear canal. Easiest to understand. Some people call it their ‘ear hole’.

Ear-Drum

The eardrum is basically a membrane that helps transmit sound into the oval window. The reason for its name would be that it looks like a drum.

These kind of drums:

Oval Window

The oval window is the beginning of the inner ear. From the image, you can see that the Cochlea comes after it. If you are wondering, Cochlea means snail in latin.

The nerves

They are basically used to transmit the sound messages to the brain.

Hearing aids Hearing aids come in play when people

start to complain of hearing problems. A hearing aid is basically a miniature

microphone linked to an amplifier that makes sound louder.

A cochlea implant (another hearing aid) is a tiny radio receiver fitted under the skin that receives radio signals from the earpiece under the ear. The implant then converts the signals to electrical pulses that trigger signals along the nerves to the brain.

And they work together, the hearing aid and the cochlea implant.

A story about the hearing aid

In the USA, there was a man named Henry Koch that complained of hearing music in his head. Test had showed that a tiny lump of carborundum, a hard block chemical from a dentist drill had stuck in his tooth. The crystals in the chemical were picking up and boosting the power of radio waves from a nearby transmitter. This triggered vibrations which he heard as music.

Sound waves

A sound wave happens when tiny air molecules are shoved together and bump apart again. As they leap apart some molecules bump into others further away. So you would get a wave of bumpy molecules moving outwards like the ripples on a pond.

Sound waves

Scientist use a machine called oscilloscope to measure sound waves. The sound waves make a beam of electrons that allows them to see a wave.

This is a sound wave:

Sound waves

From the image, basically :Faster vibrations=closer together peaks=higher frequency=higher pitch of soundSlower vibrations=peaks further apart=lower frequency=lower pitch of sound

Sound waves

High frequency sounds are sounds like: A mouse squeaking A human squeaking after seeing a mouse A bike chain in need of oil

Low frequency sounds are sounds like: A bear growling A male growling Our stomach growling

Decibels

Decibels, in a casual way of expressing it, would be how loud something is. Taking a scene from a classroom, it can show how much decibels are produced.

The next slide…

Type of noise Decibels Effect on student

I accidently drop paper on the ground.

10 db No one hears. Pick it up later

I whisper to someone during the lesson

20-30db Ssssh!! People can hear us!

I start chatting with a friend

60db My teacher can hear this!!

The whole class start chatting

75db OOH CRAP!! Take cover

Teacher yells to make us shut up

90db If he yells for too long I could suffer damage to the sensors of my cochlea.

Everyone was made to stay back for self study.

0db No one dares to speak

Airliner narrowly misses the school.

130db Ouch!! My ear drums are about to burst.

Sound in nature

Similar to humans, animals make noise too! And if you are complaining that we make too much noise, they make louder noises!!

Sound in nature-Animals

The Frog. It’s loud croak is made louder thanks to their vibrating air-filled pouches in their throat.

The rats. It is famous for it’s squeak that has a high frequency that sometimes is too loud for us to hear.

Song birds. As the name goes, they can sing, because of their singing syrinxes, which is the skin stretched over their windpipes.

Sound in nature- Animals Howler monkey. It’s voice is so loud that

these monkeys can be heard at a distance of 15km away from them.

Woodpeckers. More than making sounds from their own vocal organs, they make a repetitive sound by pecking a tree constantly using their toughened beak.

Cicadas. They are insects that make sounds using the vibrating sound inside their abdomens.

Echoes

Facts about them: An echo is made by sound waves

bouncing off a surface in the same way light bounces of a mirror.

An old castle in Milan, Italy has walls that trap the sound waves so they continue bouncing backwards and forwards about 40 times.

Alpine horns, those long horns that people in Switzerland use, use echoes to boost their range.

Echoes

Fog horns used echoes to carry their message by making the sound waves bounce of cliffs and rocks, to help warn of danger ahead.

Thunder uses echoes too! It is by bouncing the sounds of the clouds.

Bibliography

Horrible Science- Sounds Dreadful Wikipedia- http://

en.wikipedia.org/wiki/Ear Google images

The End

Hope that this ACE was beneficial!!