We produce sounds whenever we are doing something. When we get up in the morning, sound is produced by brushing teeth;when we eat, we hear the sounds we produce when eating; when we go to a club and play some rock and roll, different kinds of sounds are produced. Hereby, we can basically conclude that motions will produce sound. A sound comes from the vibration of an object, which can make the air or another substance around the object vibrate. The vibration of the air moves outward in all directions in the form of a wave, and that is what we call soundwave.
All kinds of waves like microwave are related to energy and so is sound wave. A sound wave is a transfer of energy as it travels away from the vibrating source(s).Once the sound wave is produced, it will travel through all kinds of media (solid, liquid & gas). As sound waves move through a medium the particles vibrate forwards and backwards. And once the wave travel all the way through our ears after getting through the other media, we are going to hear the sound.
There is one more important thing to point out. The further a sound wave travels, the harder we are going to hear a sound. That is because the travel of sound is basically the travel of energy. Sound wave is losing energy as it travels. Once all the energy is consumed, it will not be able to travel further, and it won't make our eardrum vibrate, and that is why we are not going to hear sound from really really far away. Just like when we are in the subway deeply under the ground, our cell phones can't receive the signal (which is also energy) transmitted from the signal towers far away above the ground.