Question

4.
What is an echo?
5.
6.
How do bats fly safely in darkness?
What are wind instruments?
What causes sound pollution?
7.​

Answer 1

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1.In audio signal processing and acoustics, echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the listener.

2.Bats fly safely in darkness because these have fine sense of locating echoes. They produce high pitched sounds. The sound bounce off the objects they hit and return to them as an echo. Echo location helps bats to locate objects in darkness and fly safely at night.

3.a musical instrument in which sound is produced by the vibration of air, typically by the player blowing into the instrument

4.Due to increasing noise around the civilizations; noise pollution has become a matter of concern. Some of its major causes are vehicles, aircraft, industrial machines, loudspeakers, crackers, etc. Some other appliances also contribute to noise pollution like television, transistor, radio, etc. when used at high volume. and reffer to the attachment

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Answer 2

Answer:

• echo is a reflection of sound that arrives at the listener with a delay after the direct sound.

• Bats fly safely in darkness because these have fine sense of locating echoes. They produce high pitched sounds. The sound bounce off the objects they hit and return to them as an echo. Echo location helps bats to locate objects in darkness and fly safely at night

• A wind instrument is a musical instrument that contains some type of resonator in which a column of air is set into vibration by the player blowing into a mouthpiece set at or near the end of the resonator. 

• Due to increasing noise around the civilizations;noise pollution has become a matter of concern. Some of its major causes are vehicles, aircraft, industrial machines, loudspeakers, crackers, etc. Some other appliances also contribute to noise pollution like television, transistor, radio, etc. when used at high volume.

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