Abstract: A oscillator in a liquid includes an actuator element oscillating in a reciprocating manner, and a sound-producing element attached to the actuator element, whereby the actuator element generates a motion in the sound-producing element for producing a sound. The oscillator is made open, whereby the pressure of liquid acts both on a first surface and on a second surface of the wall of the sound-producing element while the sound source is in the liquid. The material and/or structure of the wall of the sound-producing element is provided to be such that the distance between the first surface and the second surface of the wall varies as sound is produced.

Abstract: A oscillator in a liquid includes an actuator element oscillating in a reciprocating manner, and a sound-producing element attached to the actuator element, whereby the actuator element generates a motion in the sound-producing element for producing a sound. The oscillator is made open, whereby the pressure of liquid acts both on a first surface and on a second surface of the wall of the sound-producing element while the sound source is in the liquid. The material and/or structure of the wall of the sound-producing element is provided to be such that the distance between the first surface and the second surface of the wall varies as sound is produced.

Abstract: A sound source comprising an actuator element (1) that vibrates in a reciprocating manner such that the distance between the ends of the actuator element (1) varies. To the ends of the actuator element (1) there is attached a spring element (3) that moves by the action of the actuator element. In lateral view the spring element (3) is substantially rectangular. The ends (3a) of the spring element rectangle are elastic and so are the sides (3b) of the rectangle. The ends (3a) and the sides (3b) are joined together by substantially rigid corners (3c).