Sound can be by soft materials like cloth and by traced materials like steel.

Muffled, amplified

Explanation: When yelling against something like a cloth pillow, the sound is muffled. Whereas if you set your phone into a metal cylinder the sound is amplified off the edges of the metal. Causing it to sound louder.

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )