A device for actively reducing sound transmission, provided with a first
and second wall (3, 5) enclosing an inner space (1, 2), wherein at least
the second wall (5) is provided with actuators (6), for instance
eletromagnetic actuators and/or piezoeleteric elements, wherein the said
inner space is provided with at least one inner wall (4) to divide this
space into at least two layers of air (1, 2), which inner wall (4) is
arranged such that the layers of air (1, 2) are in fluid connection with
each other.