A speaker apparatus has a container holding a volume of ferrofluid, a
permanent magnet suspended in the ferrofluid, and a magnetic excitation
apparatus proximate the container. Operation of the excitation apparatus
causes movement of the permanent magnet, translated through the
ferrofluid to walls of the container, which walls act as resonators
creating sound waves in surrounding medium. Audio production is
accomplished placing a ferrofluid and a permanent magnet in a container,
placing an excitation apparatus in proximity of the permanent magnet, and
driving the excitation apparatus to cause movement of the permanent
magnet translated through the ferrofluid to walls of the container, which
walls act as resonators creating sound waves in surrounding medium.