Crystal Earphones are used in the construction of the crystal radio and in some science experiments such as listening to electric fish. This electronics video tutorial provides a basic introduction into the piezoelectric effect which uses crystals to convert mechanical energy into electricity.

Crystal Earphones are so sensitive and require so little power to operate that you can hear a small 'click' just by touching the two bare leads together.Ĭrystal radios will not work with modern earphones or 'earbuds' as they are designed to operate with amplified audio sources found in today's electronic devices. Sensitive earphones have a very high impedance, which is measured in ohms and should not be used directly with a modern amplified radio. They are in fact many times more sensitive than even the most sensitive magnetic earphones, dynamic earphones, or electrostatic earphones that you may use on your iPod or iPhone. Some naturally piezoelectric occurring materials include Berlinite (structurally identical to quartz), cane sugar, quartz, Rochelle salt, topaz, tourmaline, and bone (dry bone exhibits some piezoelectric properties due to the apatite crystals, and the piezoelectric effect is generally thought to act as a biological force sensor). Piezoelectric earphones, also known as crystal earphones, ceramic earphone, and piezo earpieces are the most sensitive earphones. Ceramic earphone/Crystal earpiece for Transistor and Crystal Radios, Sensitive Electronics Projects, Lab research, and other DIY experiments requiring a very sensitive high impedance earpiece.

Piezo crystal