e/Crystal earpiece

Information
has gloss	eng: A crystal earpiece, more properly called a piezoelectric earphone, is a headphone that produces sound by using a piezoelectric crystal, a material that changes its shape when electricity is applied to it. Piezoelectric materials that have been used in crystal earphones include Rochelle salt, quartz, and barium titanate.
lexicalization	eng: crystal earpiece
instance of	e/Headphones