Which of the following devices has an acoustic sensor that provides input by converting sound into
electrical signals?

A.
Microphone

B.
Trackball

C.
Webcam

D.
Sound card

Explanation:

Microphone has an acoustic sensor that provides input by converting sound into electrical signals.
Answer option C is incorrect. Webcam is a low resolution video camera used to provide visual input
that can be easily transferred over the internet.
Answer option B is incorrect. Trackball is a pointing device consisting of an exposed protruding ball
housed in a socket that detects rotation about two axes.
Answer option D is incorrect. A sound card is a computer expansion card that facilitates the input
and output of audio signals to and from a computer under control of computer programs.
Reference: “http://en.wikipedia.org/wiki/Computer_hardware”