Concepts about sounds and how it works

When we produce sounds, they travel through the air in sound waves. Sound itself is energy; therefore it tends to spread all around. The direction of sound waves is generally omnidirectional, which means they travel in all directions. However, no matter how they travel, they preserve their variations of pressure for the sound it is producing.

Ever wondered why we hear persistent echoes in an enclosed room when we make a sound? This phenomenon is due to the ability of sound waves to reflect against surfaces. Because there is no other way for the pressure to escape, the echoes are actually reflections of the waves of the walls in another direction. This is known as reverberation.

If a sound wave hits an uneven surface, the angles of reflection varies with the angle of the surface. If a sound wave hits a completely straight surface, the angles of reflection will just rebound in the exact opposite direction.

However, if it was to bounce off a parabolic disc, all of the sound waves will reflect towards a designated location, which is the focus. This property is extremely important because the refocusing of the wave can amplify the signal. For example, if a faint sound wave hits a parabolic disc, all of the waves will be reunited at the focus and amplified. Because the sound waves preserve their pressure configuration, the signal will turn out to be uniform and clear.