An arrangement for headphones for converting frequency modulated audio oscillations into amplitude modulated oscillations, and particularly for rendering audible the vibrato of electronic musical instruments, such as electronic organs, includes a housing having an electroacoustic transducer therein with a diaphragm having a smooth frequency response zone which is connected to at least one mechanical transit-time member having a transit time from one end to the other not greater than 20 ms. The transit-time member is advantageously a helical spring which extends axially through the electroacoustic transducer or through a central ferromagnetic core thereof. The portion of the spring within the core is advantageously made of a thicker wire and of a smaller diameter than the remaining core so that it does not contact the walls thereof.
