The invention relates to a portable tight device (1) comprising a housing (2) with an electro-acoustic transducer (21) mounted therein. Said electro-acoustic transducer is separated from an input cavity (11) in a fluid-tight manner by means of a deformable membrane (15). The input cavity is embodied inside the housing and communicates directly with the outside. The electro-acoustic transducer and the input cavity are disposed in a collateral manner such that at least one part of the transducer and the cavity respectively, whose thickness is predetermined, is disposed in a same section (28) of the housing and an acoustic channel links the transducer to the membrane in order to transmit acoustic vibrations.