Why does sound always move at the local speed of sound in a medium (in other words, why is there a set speed of sound for certain medium)? I understand that sound is a compression wave, but shouldn't a louder sound (i.e. one with a higher amplitude) move faster? What about a higher pitch noise (i.e. one with a higher frequency)? Is there a way to create shock waves without moving something through a medium at greater than the local speed of sound? Is the speed of sound the limit of a mechanical waves propagation speed? Thanks in advance for the answers!