The voice drop that happens to EVERYONE during puberty (but more so in male bodies) can actually extend way beyond puberty. The changes are driven by hormones (mainly testosterone) that cause the voice box to enlarge and the vocal cords to thicken. 

Another thing that’s super common during puberty (but can happen throughout your life) is voice cracks. They’re super common and completely beyond your control. There are some muscles that control the vocal cords, and sometimes they spasm—causing the vocal cords to tighten and squeak! Don’t worry if it happens to you, because it happens to us all!