Why is my cousins voice squeaky/ sounds like his 10 and his 15

He hasn't hit puberty

Explanation:

When you hit puberty your voice gets deeper and things change

High-pitched voices exist thanks to vocal cords that aren’t as long, strong, or ready for good vibrations as others, Ingo Titze, executive director of the National Center for Voice and Speech, told Fatherly. Now, size isn’t everything.

answer; i do believe the correct answer is (25) times faster;