- Aerated Water
- Air Engine
- Air Table
- Are you Hot or Not?
- Balancing Act
- Bending Beams
- Block the gap
- Braille
- Bridge the Gap
- Chalk Wall
- Changing Faces
- Chaotic Motion
- Circle of Discovery
- Circle of Discovery- The Internet
- Circle of Discovery-Bridge Design
- Circle of Discovery-Ideas hub
- Circle of Discovery-Internet
- Circle of Discovery-Medicine
- Circle of Discovery-photography
- Circle of Discovery: Design - Earthquake
- Circulation
- Colour Wheel
- Communication Codes
- Communication Dishes
- Computer
- Crystallography
- Digestive System
- Down the Drain
- Electromagnetic Spectrum
- Fibre Optics
- Flight Simulator
- Gear Table
- Handshake Mirror
- Harmonograph
- High Flyer
- Hit the Target
- Horizontal Periscope
- Human Battery
- It's Electric
- Larger Than Life
- Lift Me Pull You
- Light Table
- Lock Box
- Making Waves
- Mini Harmonograph
- Mobile Phone
- Move It
- Nervous System
- Newtons Cradle
- Organ Pipe
- Organ Pipe Tune
- Oscillating Pendulums
- Pendulums
- People Power
- Periscope
- Prove Pythagoras
- Radar
- Radio Station
- Reactable
- Reflection Refraction
- Robot Arm
- Science of Sport
- Sensation
- Simple Camera
- Simple Circuits
- Smoke Tunnel
- Solar Energy
- Sound Waves
- Structures and Stresses
- Telescope
- The Exhibition
- The Eye
- The Lung and Chest Cavity
- The Wheel Race
- Thermal Imager
- Tornado
- Tower of Hanoi
- Universe Wall
- Up and Down
- Vertical Periscope
- Viscosity
- Viscosity Plungers
- Volume and Mass
- Vortex
- Watch Your Waste
- Weight Lifter
- Wheels Within Wheels
- Wind Tunnel
Organ Pipe
Organ Pipe demonstrates the behavior of sound in a tube
Activity.... Do - Think - Learn
Sound is produced when air vibrates inside a tube. How high or low the sound is (its pitch or frequency) depends on the length and diameter of the tube.
How will the sounds change as the length is altered?
How does the amount of air affect the sound?
Is the sound louder at some frequencies?
The Science Bit
The organ produces sound by forcing air through pipes or flutes of different sizes. Air is pushed through pipes by bellows which are supplied by a fan operated by foot pedals or electric. The organists will press the keys to open a vent so air can travel through a particular pipe, producing the sound. All sound is caused by vibrations. The source that sends the vibrations is disturbing the surrounding air so much that sound waves are formed. If these vibrations reach the ear they are perceived as sound. The speed of the vibrations is the same no matter how loud or quiet a noise is. A pure sound has three basic properties, one of which is pitch. The pitch of a sound depends on the rate the vibrations are made and is measured in hertz (Hz). The higher a sounds frequency then the higher the pitch of the sound will be.
The ear responds to the vibrations in the air and they are translated into nerve signals and carried to the brain. A human’s ear has three parts:
- Outer ear
- Middle ear
- Inner ear
If a loud noise is produced then the ear reacts automatically by muscles behind the ear drum contracting. This helps to prevent any injury to the ear. In the middle ear there are three small bones, the hammer, anvil and stirrup. These bones vibrate together to magnify the sound by around twenty times.
Curriculum Links
ourselves
- That we have five senses which allow us to find out about the world
Sound and Hearing
- That there are many different sources of sound
- That there are many ways of describing sounds
- That we can make sounds in a variety of ways
- To explore sounds using the sense of touch
- That we hear with our ears
- To turn ideas about hearing into questions that can be tested
- That some sounds can be heard from a long distance
- That sounds seem louder the nearer you are to the source
- That sounds get fainter as they travel away from a source
- To explore sounds using their sense of hearing
- To make observations of sounds by listening carefully
- That there are many different ways of making sounds
Changing Sounds
- That vibrations from sound sources travel through different materials to the ear
- That the term ‘pitch’ describes how high or low a sound is
- That high and low sounds can be loud or soft
- To describe how the pitch of notes on an instrument can be altered by changing the length of air column vibrating
- That sounds can be made by air vibrating
- That sounds are made when objects or materials vibrate
- To suggest how to alter the pitch of a sound made by air vibrating and to test prediction
- To listen carefully to sounds made, to record results in a suitable table and decide whether these support the prediction made
Last Modified: 28/07/2011
