Sensor Info

A microphone, colloquially mic or mike (/ˈmaɪk/),^[1] is an acoustic-to-electric transducer or sensor that converts sound in air 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, two-way radios, megaphones, radio and television broadcasting, and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors.
Most microphones today use electromagnetic induction (dynamic microphones), capacitance change (condenser microphones) or piezoelectricity (piezoelectric microphones) to produce an electrical signal from air pressure variations. Microphones typically need to be connected to a preamplifier before the signal can be amplified with an audio power amplifier or recorded.

Condenser

Electrostatic

Capacitor

DC-Biased

Dynamic

Ribbon

Carbon

Piezo

Fiber-Optic

Laser

Liquid

MEMS

Speakers

Noise Cancelling

Contact

Parabola

Wireless

Throat

Lavaliers

 

 

Microphone polar patterns

• 

  Omnidirectional
• 

  Bi-directional or Figure of 8
• 

  Subcardioid
• 

  Cardioid
• 

  Hypercardioid
• 

  Supercardioid
• 

  Shotgun

A microphone's directionality or polar pattern indicates how sensitive it is to sounds arriving at different angles about its central axis. The polar patterns illustrated above represent the locus of points that produce the same signal level output in the microphone if a given sound pressure level (SPL) is generated from that point. How the physical body of the microphone is oriented relative to the diagrams depends on the microphone design. For large-membrane microphones such as in the Oktava (pictured above), the upward direction in the polar diagram is usually perpendicular to the microphone body, commonly known as "side fire" or "side address". For small diaphragm microphones such as the Shure (also pictured above), it usually extends from the axis of the microphone commonly known as "end fire" or "top/end address".
Some microphone designs combine several principles in creating the desired polar pattern. This ranges from shielding (meaning diffraction/dissipation/absorption) by the housing itself to electronically combining dual membranes.

Schematic: https://www.sparkfun.com/datasheets/BreakoutBoards/Amplified-Mic-Electret-v14.pdf

Data/Calabrate: http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Sound/CEM-C9745JAD462P2.54R.pdf