Sound Notes

• Sound waves travel at different speeds in different substances.
• The speed of sound depends on various factors such as temperature, nature and physical state of the substance, etc.
•  Sound waves travel fastest in solids and slowest in gases.

• Sound can be of different types- soft, loud, pleasant unpleasant, musical, audible (can be heard), inaudible (cannot be heard), etc.

Audible and Inaudible Sounds:

• Unpleasant, discomfort – causing sound from any source is called noise.
• Sustained presence of harmful, unwanted, or annoying noise in the environment noise in the environment is called noise pollution.

Sources of noise pollution:

• Any object that produces a noise is a potential source of noise pollution. Some examples are automobiles, blaring loudspeakers, television and radio, air coolers, and air conditioners.

Harmful effects of noise pollution: