Question

Um... Hello again!
Lets melt some brain. {*kinda rhymes}

I never speak unless spoken to, many have heard me but none have seen me.
What am I?

Try this riddle ​

Answer 1

Answer:

the answer is an echo that means if any sound is produced by us ,it reflects back ,so unless we speak it wont be heard. many people have heard sounds but no one can see sound waves.....

this riddle i learnt in my schooling ..tq