An electromagnetic vibrator for use in a portable communication device (90) comprising a housing (20,30,40,50,60,70,80) comprising a track directed in a first dimension, a coiling (22,82) comprising at least one coil turn, oriented in a second dimension essentially perpendicular to the first dimension, coiled around the track and being arranged to receive an electric voltage, a permanent magnet assembly (26,32,34,42,52,62,72,84) arranged for motion along the track to which said permanent magnet assembly is tightly fitted, and a ferrofluid mixture placed between the track and the permanent magnet assembly (26,32,34,42,52,62,72,84), allowing motion of the permanent magnet assembly (26,32,34,42,52,62,72,84) in the first dimension in dependence of the electric voltage as supplied to the coiling (22,82).