Noise pollution is defined as annoying or harmful levels of noise. The cumulative effects of noise pollution can affect our physical and mental health. Reducing noise pollution can be achieved through regulation, improved building methods, better product design, noise barriers and better planning.

Modify the paths by which the noise travels through the air to the people exposed, eg: Erect enclosures around machines to reduce the amount of noise emitted into the workplace or environment. Use barriers and screens to block the direct path of sound. Position noise sources further away from workers.

At the very bottom of this reality are physical forces and symmetries—and noise. They’re equally fundamental. The very universe began as a random quantum fluctuation.

The vacuum of outer space has essentially zero air. Because sound is just vibrating air, space has no air to vibrate and therefore no sound.

Orfield Laboratories

The vibrations are then transcribed by the neurons in our brain so as to give us a perception of sound. So if you were to imagine a world without vibrations (in your terms sound), this universe would not know the presence of heat, there would be no life as nothing can survive at zero Kelvin.

Sound is defined as vibrations that travel through air or another medium and can be heard when they can reach when they reach a person’s or animal’s ear. We can’t imagine a world without sound because it plays a important and vital role in our lives. We are surrounded in a sea of sound.

Sound is important because it engages audiences: it helps deliver information, it increases the production value, it evokes emotional responses, it emphasises what’s on the screen and is used to indicate mood. When put to good use, language, sound effects, music, and even silence, can elevate your video dramatically.

Everything we know is founded upon the human body’s ability to process sensory information. Sound is vital to sharing information, interacting with other people, creating art, regulating schedules, and countless other aspects of life.

What are the applications of sound?

• Sonar is used in navigation, forecasting weather, and for tracking aircraft, ships, submarines, and missiles.
• Sound finds many applications in entertainment electronics, radio, cassette, etc.
• Sound is very useful in communication.

If you have normal hearing, you probably tend to overlook many sounds in your everyday living environment….Some Common Sounds.

Indoor sounds	Some softer sounds	Human noises
smoke alarm	hum of a computer	people talking in another room
telephone	ceiling fan	running

Answer: Acoustic instruments, Electrical instruments, Living beings like animals and birds using their vocal cords, Man-made sources like machines, any vibration caused by wind are five sources of sound.

Sources of Sound Energy

• Acoustic Instruments. •••
• Electronic Instruments. Electrical vibrations are the starting point of sounds from electronic organs and synthesizers.
• Living Things. Animals and people make sounds with their vocal cords, their mouths and other body parts.
• Machines.
• Nature.

Three components are needed for sound to be heard:

• A source – where the sound is made.
• A medium – something for the sound to travel through.
• A receiver – something to detect the sound.

Sound waves need to travel through a medium such as solids, liquids and gases. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly.

Sound is a type of energy made by vibrations. These vibrations create sound waves which move through mediums such as air, water and wood. When an object vibrates, it causes movement in the particles of the medium.

All sounds originate in the vibrations of material objects. The source of all sound waves is vibration. In a piano, violin, or guitar, a sound wave is produced by vibrating strings. In a saxophone, a reed vibrates; in a flute, a fluttering column of air at the mouthpiece vibrates.

The source of sound can be both natural or man-made. Few examples of natural sound sources are humans, animals, flowing water, avalanches and many more. Sources of man-made sounds are vehicles, factories, fans, explosions, etc.

In the early years of the 21st century, the definition of the soundscape was broken down into three components: the geophony, non-biological natural sounds that include the effects of water by a stream or waves at the ocean, the effects of wind in the trees or grasses, and sound generated by the earth, itself, for …

The speed of sound depends on the medium in which it is transported. Sound travels fastest through solids, slower through liquids and slowest through gases.

Sound waves are travelling vibrations of particles in media such as air, water or metal. So it stands to reason that they cannot travel through empty space, where there are no atoms or molecules to vibrate.

While sound moves at a much faster speed in the water than in air , the distance that sound waves travel is primarily dependent upon ocean temperature and pressure. This causes the speed of sound to increase and makes the sound waves refract upward.

Selected Sound Speeds in Metals

Metal	Density (gm/cm3)	Vl m/s
Aluminum, rolled	2.7	6420
Brass (70 Cu, 30 Zn)	8.6	4700
Steel, 347 stainless	7.9	5790

Laser beams

The speed of sound through air is about 340 meters per second. Light will travel through a vacuum at 300 million meters per second. So they’re totally different scales. No information can propagate faster than the speed of light.

Diamond