A Variety of Bouncy Sounds
Bouncing sounds that reinforce the original sound
Bouncing sounds reinforce the original sound when the bouncing sound is heard almost simultaneously, making the original sound louder. This noise occurs when the wall distance to the sound source is less than 10 meters. For example our voices will be heard louder in the room or the sound of bathing and the sound of the train louder in the tunnel.
If the incoming sound is narrowed to a normal line (coming angle = 0), then the sound of the bounce is perpendicular to the normal line (the angle of return = 0), in other words the sound of the bounce will reverse the direction of the sound. If the angle is greater than 0, the sound of the bays will not turn in the direction of the sound coming again.
Sound reflection occurs when a sound hits a wall or a hard surface. Such hard surfaces, such as stone, iron, zinc, and glass.
Echoes or kerdam
Reverberation or kerdam occurs if the distance of the wall to the sound source is rather far (10 m - 25 m). Reverberation is a sound that is heard less clearly due to some sound reflected along with the original sound so that it interferes with the original sound.
Echoes occur in large buildings that are closed, such as meetinghouses and theater buildings. To avoid reverberation, on the inside walls of cinemas, radio or television studios, and recording studios are covered with silencer. Damping materials that are often used include wool, cotton, cardboard, rubber, and glass.
Echo
If the distance of the reflecting wall is far enough, there will be a sound reflected after the original sound is said (emitted). The sound that bounces after the original sound is called an echo. The echoes sounded like real sounds. Echoes can occur on steep mountain slopes, ravines and other places.
Sound Wave Characteristics
Measuring the speed of sound propagation
How to measure the sound propagation fast in this principle is quite easy, namely by measuring the time it takes the sound from exiting the sound until returning to its original place. then we measure the distance of the sound source to the reflecting site. by doing this measurement we can find out the speed of sound propagation in the air.
v = fast sound propagation (m / s)
s = distance (m)
t = time (s)
If the sound propagation is known, sound reflection can be used to measure distances
By measuring the time it takes the sound from being emitted to being recaptured, the distance of the reflector from the sound source can be calculated.
Fast sound propagation in solid substances
Suppose an external force F is applied to the end of an object with a cross-sectional area A so that the end of the rod moves with a speed u and causes a dense pulse of sound waves to propagate along the rod with a speed ʋ. In time t pulses travel a distance of ʋt and length of the metal rod, compressed by ut
Fast sound propagation in solid substances
E = modulus of elasticity of metal material (N / m2 or Pa) and
ρ = density of metal (Kg / m3)