Q: What hits the eardrum and causes it to vibrate?


Read this paragraph and choose the correct option from the provided answers:

The eardrum is like the head of a drum. It is a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear.

 Choices:

- cilia

- decibels

- microwaves

- sound waves


A:
sound waves