(pē, ∂ zō i lek’ trik or pī e, zō e lek’ trik) 1. The property of a dielectric that generates a voltage across it in response to a stress, and vice-versa. In a hydrophone the stress is produced by the pressure, and in an accelerometer the stress is produced by the inertia of the reaction mass. Piezoelectric transducers are commonly made of barium titanate or zirconate. Also called electrostrictive. From the Greek ‘‘to press.’’ 2. An impulsive seismic energy source that is comprised of a high-voltage powered transducer held against the surface of the earth.