Editing Microphone (section)

=== Piezoelectric <span class="anchor" id="Piezoelectric microphone"></span>===
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[[File:Astatic crystal mic.jpg|thumb|Vintage [[Astatic Corporation|Astatic]] crystal microphone]]

A '''crystal microphone''' or '''piezo microphone'''<ref>{{cite journal |last1=Lee |first1=Woon Seob |last2=Lee |first2=Seung S. |title=Piezoelectric Microphone Built on Circular Diaphragm |journal=Sensors and Actuators A |volume=144 |issue=2 |date=2008 |pages=367–373 |url=http://www.pitt.edu/~qiw4/Academic/ME2080/ZnO%20circular%20microphone.pdf |archive-url=https://web.archive.org/web/20130717185137/http://www.pitt.edu/~qiw4/Academic/ME2080/ZnO%20circular%20microphone.pdf |archive-date=July 17, 2013 |doi=10.1016/j.sna.2008.02.001 |bibcode=2008SeAcA.144..367L |access-date=March 28, 2023 }}</ref> uses the phenomenon of [[piezoelectricity]]—the ability of some materials to produce a voltage when subjected to pressure{{efn|An example of this is [[potassium sodium tartrate]], which is a piezoelectric crystal that works as a transducer, both as a microphone and as a slimline loudspeaker component.}}—to convert vibrations into an electrical signal. Crystal microphones were once commonly supplied with vacuum tube (valve) equipment, such as domestic tape recorders.  Their high output impedance matched the high input impedance (typically about 10&nbsp;MΩ) of the vacuum tube input stage well. They were difficult to match to early [[transistor]] equipment and were supplanted by dynamic microphones, and later small electret condenser devices. The high impedance of the crystal microphone made it very susceptible to handling noise, both from the microphone itself and from the connecting cable.{{cn|reason=Are we sure this is about impedance?|date=April 2025}}

Piezoelectric transducers are often used as [[contact microphone]]s to amplify sound from acoustic musical instruments, to sense drum hits and trigger electronic samples, and to record sound in challenging environments, such as underwater under high pressure. [[Pick up (music technology)#Piezoelectric pickups|Saddle-mounted pickups]] on [[acoustic guitar]]s are typically piezoelectric devices that contact the strings passing over the saddle. This type of microphone is different from [[Pick up (music technology)#Magnetic pickups|magnetic coil pickups]] commonly visible on typical [[electric guitar]]s, which use magnetic induction, rather than mechanical coupling, to pick up vibration.<!--[[User:Kvng/RTH]]-->