1). Lower sound volume means lower wave amplitude.
2). The pitch of the sound we sense is directly connected to the frequency.
Low frequency is perceived as low pitch.
3). It is not possible to hear the band play on the moon. Sound needs
something to travel through. When we hear sound, it is most often traveling
through air. There's no air on the moon, so you can't hear any sound, even
if it comes from right next to you.
I can see another big problem on the moon ... it would be kind of hard to
get your guitar, or the mouthpiece of your trumpet, inside your space suit.
4). From your mouth to the pillow, the sound waves travel through air.
When they reach the pillow, the waves are absorbed by the cloth and the
feathers, and they don't go anywhere else. So nobody hears you scream.
5). The sound waves travel through air, as always. When they reach a
hard surface, like the rock wall of a cave or even the wall of the gym in
your school, the waves bounce off of the wall and continue moving, but
in the opposite direction. The bounce is called 'reflection', just like light
bouncing off of a mirror. When the sound waves return to you, you hear
them, and it sounds like your own voice again. You call it an "echo".
