The correct answer is Microphone.MicrophoneA microphone, colloquially called a mic or mike (/ma?k/).It is a device that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, radio, and television broadcasting.They are also used in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic sensors or knock sensors.Additional Information Optical character recognitionOptical character recognition or optical character reader is the electronic or mechanical conversion of images of typed, handwritten, or printed text into machine-encoded text, whether from a scanned document, a photo of a document, a scene-photo or from subtitle text superimposed on an image.?Bar code readerA barcode reader (or barcode scanner) is an optical scanner that can read printed barcodes, decode the data contained in the barcode and send the data to a computer.Like a flatbed scanner, it consists of a light source, a lens, and a light sensor translating for optical impulses into electrical signals.Additionally, nearly all barcode readers contain decoder circuitry that can analyze the barcode's image data provided by the sensor and sending the barcode's content to the scanner's output port.Optical mark recognitionOptical mark recognition (also called optical mark reading and OMR) is the process of capturing human-marked data from document forms such as surveys and tests.They are used to read questionnaires, multiple-choice examination papers in the form of lines or shaded areas.