Browse Definitions:
Definition

microphone

Contributor(s): Matthew Haughn

A microphone is a device that translates sound vibrations in the air into electronic signals or scribes them to a recording medium. Microphones enable many types of audio recording devices for purposes including communications of many kinds, as well as music and speech recording.

Frequently, microphones are designed for a given purpose. One of the main considerations, aside from the type of device, is what is being recorded. Directionality of microphones is one such consideration in microphone design. Omnidirectional  microphones are suited to recording all sounds in an area but poor for focusing on a single subject amongst background noise. Directional, bidirectional and shotgun microphones are suitable for interviews. However, the same effect is often achieved with two unidirectional devices, such as cardioid microphones.

The first electronic microphone was a liquid-based mechanism that used a diaphragm attached to a current-charged needle in a diluted sulfuric acid solution. This early microphone was not able to reproduce intelligible speech.

Since then, there have been and continue to be many types of microphone technologies, some of which are described below:

The first viable diaphragm microphones used a sheet of metal attached to a needle which scribed transmitted vibrations to a foil recording medium. When the needle moved over the foil after the scribing, the process was reversed and translated back to sounds again through the same metal diaphragm.

Carbon microphones were used in telephones for over one hundred years. These devices used the variable electrical resistance of carbon under pressure between metal plates to translate airborn sound waves into a electrical signal.

Condenser microphones use the varied electrical charge of a capacitor with a diaphragm acting as a one of the plates of a capacitor. The plate is biased by a fixed charge, often from a battery which also amplifies the signal. Capacitance varies with movement of the diaphragm in relation to the other plates providing the means to record the sound in electrical signal. Electret microphones used in cell phones and computers are a type of condenser microphone that use a polarized ferroelectric material.

Crystal microphones use a piezoelectric crystal that generates small amounts of electricity under compression of a diaphragm to provide the recording signal.

Dynamic microphones use a coil suspended in a magnetic field that may be attached to multiple membranes for extended frequency response. They use electro-magnetic induction to produce the signal. These microphones are well suited to stage performance.

Laser microphones use the vibrations of surfaces affected by sound waves to capture sound at distances. The lasers return at different angles due to the vibration and these changes are interpreted and translated into sound waves.

Due to similarities in function, microphones can operate as speakers. Generally, microphone-derived speakers are suited to high-frequency sounds like the STC company's microphone derived super-tweeter. Speakers can also operate as microphones, although they are generally suited for the capture of low frequencies.

Acmeschool provides an introduction to microphones:

This was last updated in December 2016

Continue Reading About microphone

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

SearchSecurity

  • computer exploit

    A computer exploit, or exploit, is an attack on a computer system, especially one that takes advantage of a particular ...

  • cyberwarfare

    Cyberwarfare is computer- or network-based conflict involving politically motivated attacks by a nation-state on another ...

  • insider threat

    Insider threat is a generic term for a threat to an organization's security or data that comes from within.

SearchHealthIT

SearchDisasterRecovery

  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

SearchStorage

  • OpenStack Block Storage (Cinder)

    OpenStack Block Storage (Cinder) is open source software designed to create and manage a service that provides persistent data ...

  • SATA Express (SATAe)

    SATA Express (SATAe or Serial ATA Express) is a bus interface to connect storage devices to a computer motherboard, supporting ...

  • DIMM (dual in-line memory module)

    A DIMM (dual in-line memory module) is the standard memory card used in servers and PCs.

SearchSolidStateStorage

  • hybrid flash array

    A hybrid flash array is a solid-state storage system that contains a mix of flash memory drives and hard disk drives.

  • 3D XPoint

    3D XPoint is memory storage technology jointly developed by Intel and Micron Technology Inc.

  • RRAM or ReRAM (resistive RAM)

    RRAM or ReRAM (resistive random access memory) is a form of nonvolatile storage that operates by changing the resistance of a ...

SearchCloudStorage

  • Google Cloud Storage

    Google Cloud Storage is an enterprise public cloud storage platform that can house large unstructured data sets.

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

Close