Piezo microphone
A piezo microphone is an electroacoustic transducer that converts pressure fluctuations in the air into corresponding electrical signals. A membrane follows the pressure fluctuations of the sound. It is mechanically coupled to a piezoelectric element that is minimally deformed by the pressure fluctuations. The electrical voltage fluctuations of the piezoelectric material (usually lead-zirconate-titanate ) are transmitted to the amplifier.
Such microphones were popular in the 1930s to 1950s. They are mechanically robust and have advantages due to their simple design. A major disadvantage of this converter technology is the high distortion factor . They are therefore not suitable for high-quality recordings and could not prevail against the carbon microphone in telecommunications technology either . Today, electret microphones dominate the mass market, as they have advantages through superior signal quality and extremely compact design.
Vibration conversion using piezoelectric elements, however, is widespread in contact sound converters. The forces acting here are usually much greater and lead to better transmission properties than can be the case with airborne sound.
literature
- Thomas Görne: Microphones in theory and practice. 8th, new, revised and expanded edition. Elektor-Verlag, Aachen 2007, ISBN 978-3-89576-189-8 .