sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation

stimulated in organs of hearing by such vibrations.

Audible Sounds are sounds that you can hear.

Inaudible Sounds are sounds that you cannot hear.

Sound comes from a series of vibrations, and all the sounds you heard in the experiment occurred because of vibrations and energy. Sound travels in waves. When a source, or something that produces sound, vibrates, it transfers its energy to the surrounding particles causing them to vibrate. Those particles then bump into the ones next to them and so on. This causes the particles to move back and forth but waves of energy to move outward in all directions from the source.

Your vocal chords and the strings on a guitar are both sources which vibrate to produce sounds. Without energy, there would be no sound. Let us take a closer look at sound waves.

A Wave is a disturbance that travels through space and time, accompanied by the transfer of energy.

Infrasonic Waves: Sound waves of frequencies below 20 Hz.

Ultrasonic Waves: Sound waves of frequencies below 20,000 Hz.

The high-pressure region, created by a vibrating object as it moves forward, and pushes and compresses the air in front of it is called a compression (C). This compression starts to move away from the vibrating object. When the vibrating object moves backwards, it creates a region of low pressure called rarefaction (R).

Very fast, repeated backward and forward movement of particles of matter.

For example, the vibration of the tuning fork creates pure sound.

The hammer hits the nail and the particles vibrate making noise.

In humans, the sound is produced by the voice box or the larynx. Voice box is at the upper end of the windpipe. Two vocal cords, are stretched across the voice box or larynx in such a way that it leaves a narrow slit between them for the passage of air.

When the lungs force air through the slit, the vocal cords vibrate, producing sound. Muscles attached to the vocal cords can make the cords tight or loose. When the vocal cords are tight and thin, the type or quality of voice is different from that when they are loose and thick.

A system for the detection of objects under water by emitting sound pulses and detecting or measuring their return after being reflected.

o Different musical instruments create different sound vibrations

o Wind instruments by blowing and vibrating the air e.g. flute, saxophone, organ

o String instruments by touching and vibrating the strings e.g. guitar, violin, piano

o Percussion instruments by hitting a surface. E.g. drums, cymbals, triangle