ASVAB Practice Test 2025 - Free ASVAB Practice Questions and Study Guide.

A device that converts sound waves to electric current is known as a microphone. This technology works by capturing sound waves created by vibrations in the air and converting them into an electrical signal. This conversion process typically involves diaphragm movement within the microphone, which triggers changes in capacitance or impedance, resulting in an electric current that mirrors the original sound wave's frequency and amplitude.

Microphones serve a crucial role in various applications, including broadcasting, music recording, and public speaking, allowing for sound to be captured and transmitted electronically. They are categorized into different types, such as dynamic and condenser microphones, each using slightly different mechanisms to achieve the sound-to-electric conversion.

Other devices mentioned in the options have entirely different functions. For instance, a condenser is a type of microphone, not a standalone device that converts sound. A transistor is an electronic component used to amplify or switch electronic signals, and a tuner is a device for receiving radio frequencies. These distinctions clarify why the microphone is the correct answer, given its specific role in translating sound waves into electric currents.