What Is A Microphone?

Date First Published: 26th August 2023

Topic: Computer Systems

Subtopic: Computer Hardware

Article Type: Computer Terms & Definitions

Difficulty: Easy

Difficulty Level: 3/10

CONTENTS

Types Of Microphones
History

Learn about what a microphone is in this article.

A microphone is an input device that picks up sound waves in the air and converts them into electrical signals. It then amplifies it as an analogue signal or converts it to a digital signal for it to be processed by a computer, a recording player, or speakers. They perform the opposite action of speakers, which convert electrical signals into sound waves. Microphones are often used to record voice for singing and podcasts, for VoIP applications, and for voice recognition.

Microphones can be standalone or embedded in devices. For example, smartphones and tablets have a built-in microphone located at the back of the phone. On laptops, integrated microphones are often found at the top of the display.

Types Of Microphones

The most common types of microphones are:

Unidirectional microphones - These only pick up sound in one direction. This is ideal when someone only needs to record one thing, like their voice when creating a podcast.
Bidirectional microphones - These can pick up sounds from the front and back of the microphone. This makes it ideal for recording conversations.
Omnidirectional microphones - These can pick up sounds in all directions, but they are less suitable for focusing on a single subject when there is background noise.
Dynamic microphones - These have a simple design that includes a magnet wrapped by a metal coil. They use electrical energy in the form of induction to produce the audio signal.
Condenser microphone - These rely on a sensitive vibrating diaphragm to capture sound. When sound waves hit the diaphragm, they vibrate and alter the distance between the two plates and the charge is transmitted as an electrical signal.
Ribbon microphones - Also known as ribbon velocity microphones, these contain a thin ribbon made of a thin aluminium, duralumin, or nanofilm of electrically conductive ribbon. Incoming sound waves make the ribbon vibrate, generating voltage in proportion to the velocity of the vibration.
Laser microphones - These use a laser beam to detect sound vibrations in a distant object. The lasers return at different angles due to the vibration. These changes are interpreted and translated into sound waves.
Close-talk microphones - These are designed to be used close to the mouth so that background noise is blocked out.
Clip-on microphone - A wireless microphone that is designed to be attached to the user. It usually clips onto the clothing of the user.

History

A liquid-based mechanism with a diaphragm connected to a current-charged needle in a diluted sulfuric acid solution formed the basis for the first electronic microphone. Intelligible speech could not be reproduced by this early microphone. The earliest practical diaphragm microphones recorded vibrations onto a foil recording surface using a sheet of metal fastened to a needle. After the scribing, the process was reversed and translated back into sounds using the same metal diaphragm when the needle travelled over the foil.

A wide range of microphones are available that fulfil the requirements of a number of different uses due to technological advancements in microphone design. In recent years, digital microphones have also grown in popularity as a result of their enhanced sound quality and durability. In addition, wireless microphones are now regularly employed in a range of contexts, from live performances to television production, but analogue microphones continue to have a wide range of uses due to their accessibility and affordability.