it is a power point presentation on sound

2. 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.

3. Audible Sounds are sounds
that you can hear.
Inaudible Sounds are sounds that
you cannot hear.

5. 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.

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

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

8. 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).

9. 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.

12. 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.

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

14. 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