I Need Earplugs

Does anyone know why babies sometimes SCREAM a lot?
Does anyone even know how come their voices aren't cracked after all the screaming?
Amazing, huh?

有誰知道為何嬰兒有時愛大叫?
有誰甚至知道為何他們在大叫一天後聲音不會變沙啞?
奇妙吧!