Answer:Higher the amplitude, more is the loudness. So some sounds are louder than others due to its amplitude.

The Doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. As the source of sound waves approaches a listener, the sound waves get closer together, increasing their frequency and the pitch of the sound.

Changing the amplitude of a sound wave changes its loudness or intensity. When you pluck a string gently, the sound will be softer because you have transferred less energy to the string. By using less energy, the string does not vibrate as much and will move less air than if you had plucked the same string forcefully.

The Krakatoa volcanic eruption: Not only did it cause serious damage to the island, the eruption of Krakatoa in 1883 created the loudest sound ever reported at 180 dB.

An echo is weaker than the original sound because the sound wave imparts energy to the surface from which it bounces. When a sound wave is directed at a distant surface, particles of air in the path transmit the energy to the next particle, until it reaches the surface.

The velocity of sound in dry air is approximately 343 m/s at a temperature of 25 °C. Therefore, the reflecting object must be more than 17.2m from the sound source for echo to be perceived by a person located at the source. When a sound produces an echo in two seconds, the reflecting object is 343m away.

By knowing the speed of sound and measuring the time it takes to hear the echo, you can calculate the distance of the object. A sonar device sends out a sound and automatically calculates the distance of an object.

To produce an echo, the conditions required a are: (i) There should be sufficient time gap between original and reflected sounds. For the formation of echo, the reflecting surface must be rigid such as a building, hill or a cliff. (iv) Size of the obstacle should be quite large for the echoes to be heard.

The repetition of sound caused by its reflection off a hard surface is known as echo. Factors important to get a distinct echo are: The minimum distance between the source and reflector of sound should be 17 m. The size of reflector must be large enough as compared to the wavelength of the sound wave.

(i) To hear a distinct echo, the time interval between the original sound and the reflected one must be at least 0.1 s. Echo is a repetition of sound due to the reflection of original sound by a broad and hard obstacle.

In linguistics, an echo answer or echo response is a way of answering a polar question without using words for yes and no. The verb used in the question is simply echoed in the answer, negated if the answer has a negative truth-value.

Echoes are used by bats, dolphins and fisherman to detect an object / obstruction. They are also used in SONAR (Sound navigation and ranging) and RADAR(Radio detection and ranging) to detect an obstacle.