The answer to the riddle is "an echo."
Here's why:
You speak without a mouth: An echo repeats sounds back to you, but it doesn't have a mouth to generate the sound itself.
You hear without ears: An echo can "hear" the original sound and reproduce it, but it doesn't have physical ears.
You have no body: An echo exists as a wave of sound, not a physical entity.
You come alive with the wind: Wind can affect the way an echo sounds and carries, making it seem like the echo itself is responding to the wind.
Great job thinking creatively! Did you have any other guesses before coming up with the
answer?