An electret microphone is a type of electrostatic capacitor-based microphone, which eliminates the need for a polarizing power supply by using a permanently charged material. Every cellphone and laptop has one embedded into it.
Datasheet: http://cdn.sparkfun.com/datasheets/Sensors/Sound/CEM-C9745JAD462P2.54R.pdf
Example Audio LED control project: https://negativeacknowledge.com/2008/06/11/final-lightbar-controller/
Datasheet: http://cdn.sparkfun.com/datasheets/Sensors/Sound/CEM-C9745JAD462P2.54R.pdf
Example Audio LED control project: https://negativeacknowledge.com/2008/06/11/final-lightbar-controller/
