A soundproof lock of the type that comprises a box-like body for accommodating at least one actuation element for at least one sliding latch which is pivoted on an inner wall of said box-like body and can move between an extracted configuration and a retracted configuration with respect to said box-like body as a result of corresponding translations of said actuation element along a path inside said box-like body which is defined by at least one first slot thereof within which at least one first plug is engaged which is integral with an inner wall of said box-like body: - said actuation element comprises at least one contoured second slot for the slideable accommodation of a peg for pivoting said at least one sliding latch, said sliding latch, at said peg, being provided with at least one eccentric projection which can be accommodated, in the configuration of total extraction of said sliding latch, in a respective recess of said second slot, - at least one rocker arm, which is pivoted on an inner wall of said box-like body, comprises an end tab which is contoured and adapted to abut on a corner of the edge of said sliding latch, characterized in that: - the abutment of said tab on said corner blocking the rotation of said sliding latch in the configuration in which the latch is extracted from the box-like body, - a seat of the lateral edge of said actuation element is aligned with a protruding tooth of said at least one rocker arm, a translation of said actuation element causing the abutment of said tooth against said seat, with forcing of the rotation of said rocker arm and distancing of said end tab from said corner of said sliding latch, - an element made of deformable material is interposed between the wall of said box-like body, on which said sliding latch abuts with a face thereof in the configuration of total extraction, and said face, for damping the impact between such components during the extraction of the sliding latch. - said actuation element comprises at least one contoured second slot for the slideable accommodation of a peg for pivoting said at least one sliding latch, said sliding latch, at said peg, being provided with at least one eccentric projection which can be accommodated, in the configuration of total extraction of said sliding latch, in a respective recess of said second slot, - at least one rocker arm, which is pivoted on an inner wall of said box-like body, comprises an end tab which is contoured and adapted to abut on a corner of the edge of said sliding latch, - the abutment of said tab on said corner blocking the rotation of said sliding latch in the configuration in which the latch is extracted from the box-like body, - a seat of the lateral edge of said actuation element is aligned with a protruding tooth of said at least one rocker arm, a translation of said actuation element causing the abutment of said tooth against said seat, with forcing of the rotation of said rocker arm and distancing of said end tab from said corner of said sliding latch, - an element made of deformable material is interposed between the wall of said box-like body, on which said sliding latch abuts with a face thereof in the configuration of total extraction, and said face, for damping the impact between such components during the extraction of the sliding latch.