20 August 2014LO:Sound

Chesterhouse Primary

The Ear

The Outer Ear

Pinna – collects sound and funnels it in to the ear canal.

Auditory canal - it lets sound travel from the pinna to the ear drum through its narrow tunnel. It stops infection entering the ear.

Ear drum –the ear drum vibrates when hit by sound waves coming from the auditory canal. It sends these vibrations into the middle ear.

The Middle EarThe ossicles: The 3 smallest bones in the human body. They are known as the hammer, the anvil and the stirrup because of their shape. They move the vibrations from the ear drum to the cochlea.

Eustachian tube: It lets liquid in the ear drain into the throat and keeps the air pressure on both sides of the ear drum the same.

The Inner Ear

Oval window: is a membrane that transfers the vibrations of the stirrup into the liquid in the cochlea.

Semi-circular canal: helps you to balance your body.

Cochlea: changes the physical vibrations which have come form the outer and middle ear into electrical impulses.

Auditory nerve: a pathway from the cochlea to the brain. It carries the electrical impulses.

When the electrical impulses from both ears combine in the brain, we hearSound is an energy made when something vibrates.

Sound WavesSound waves: When something vibrates, the air particles around move and bump into one another. This carries until the particles do not have enough energy to carry on moving. This movement is called a sound wave.

FrequencyFrequency: The speed of the vibration is called the frequency of a sound wave. The faster it travels the higher pitch of the sound. But when it travels slowly, the lower the pitch.

WavelengthA sound wave is made as particles bump into each other and move away from each other. A wavelength is the distance it takes to complete one full pattern. Low frequency notes have a bigger wavelength than high frequency notes.

Pitch and Tone

Tone is the quality of a sound – either music or vocal.Pitch is how high or how low the sound sounds because of the speed of its vibrations.

A Guitar

The thicker a string is, the lower the sound because it produces a sound wave with a low frequency.A guitar is tuned by loosening or tightening the strings to make the pitch higher or lower so that it matches the note each string is supposed to play.

How a guitar works: a short string makes a higher- pitched sound than a long string plucked. When a string is plucked hard its loud and when plucked soft its softer.

An African DrumIf you tighten a drum skin, it makes a higher pitch sound, so by hitting it we can produce a higher or lower pitched sound depending on how much it is stretched.

Interesting Facts about Sound1. Can sound travel under the water?

Yes sound can travel under the water. It moves four times faster through water than through the air. It can travel such long distances that whales can hear each other when they are nearly a hundred miles apart.2. Is there sound on the moon?

No, there is no sound in space. Sound needs something to travel through like air or water.3. What is the speed of Sound?

Sound travels through air at 1,120 feet (340 meters) per second.