Sound waves are longitudinal mechanical waves that require a medium such as air or water to propagate. There are two types of mechanical waves: longitudinal waves where particles of the medium move parallel to the wave direction, and transverse waves where particles move perpendicular. Interference occurs when sound waves from different sources meet and combine to produce a new wave. Constructive interference amplifies the waves while destructive interference cancels them out. Infrasonic waves have frequencies below 20 Hz and ultrasonic waves are above 20,000 Hz, the normal human hearing range. Both have applications like monitoring earthquakes and welding.

1. Sound waves

2. Mechanical Waves
 Mechanical Waves are waves which propagate through a material medium (solid, liquid,
or gas) .
 There are two basic types of wave motion for mechanical waves: longitudinal waves
and transverse waves.

3. Mechanical Waves
Mechanical waves require a physical medium. The particles in the medium can
move in two different ways: either perpendicular or parallel to direction of the
wave itself.
In a longitudinal wave, the particles in the medium move parallel to the
direction of the wave.
In a transverse wave, the particles in the medium move perpendicular to the
direction of the wave
Longitudinal  Parallel
Transverse  Perpendicular
Water waves are an example of waves that involve a combination of both
longitudinal and transverse motion

6. Sound waves
 Sound waves is a series of longitudinal or compression waves that
move through air or other materials.
 Sound does not travel through in a vacuum.

7. Electromagnetic waves

8. Standing waves/stationary waves

9. A standing wave, also known as a stationary wave, is a wave
that remains in a constant position. This phenomenon can
occur because the medium is moving in the opposite
direction to the wave, or it can arise in a stationary medium
as a result of interference between two waves traveling in
opposite directions

11. Interference of sound waves
 When two or more sound waves from different sources are present
at the same time,they interect with each other to produce a new
wave.The new wave is the sum of all the different waves.Wave
interaction is called interference.

12. Interference of sound waves
 Constructive interference occurs when two waves combine to
create a larger wave. This occurs when the peaks of two waves line
up.
 • Destructive interference occurs when two waves combine and
cancel each other out. This occurs when a peak in one wave lines
up with a trough in the other wave.

16. Infrasonics
Infrasonic are the sound waves, having frequency below those
of the sound waves that can be detected by the human ear-
i.e,below 20 hertz.
Infrasonic,covering sounds beneath 20Hz down to 0.001Hz.
This frequency range is utilized for monitoring
earthquakes,charting rocks and petroleum formation below
the earth
The waves of frequency less than 20Hz are known as infrasonic
waves.

17. Application of infrasonic waves: there are following applications of
infrasonic waves.
a Infrasonic waves are produced by large vibrating bodies.
b. Its frequency is less than 20 Hz.

18. Ultrasonic
Ultrasonic: sound waves with frequencies above the normal
human range of hearing.
Sound is generally classed as ultrasonic when its frequency
exceeds 20,000 hertz
The waves of frequency greater than 20,000Hz are known as
ultrasonic waves
Bats can produce ultrasonic waves
Dolphins also produce ultrasonic waves. They can also detect the
ultrasonic waves

19. Application of ultrasonic waves: There are following applications
ultrasonic waves.
a. Ultrasonic waves are used to establish ship to ship to communication.
b. Ultrasonic waves are used for welding plastics.
c. These waves are used to analyze the development of unborn child.
e. Ultrasonic waves are used to determine the depth of a sea.

20. Normal hearing band
Hearing range usually describes the range of frequencies that can be
heard by humans or other animals.
In humans the audible range of frequencies is usually 20 to 20,000
Hz.,although there is considerable variation between individual.