electret microphone« BACK TO DICTIONARY INDEX
(n.) Similar to a condenser microphone, an electret mic employs a permanent electrical charge, eliminating the need for an external polarizing voltage. The electret (acronym for electricity + magnet) material is similar to a permanent magnet that exhibits persistent dielectric polarization. Electret elements exhibit very high output impedance, so their circuits usually employ an integral impedance converter that requires external power to operate. This low voltage power may be supplied single-ended over an unbalanced connection, or it may operate from standard phantom power.