Vacuum therapy unit for the treatment of wounds on the human or animal body by means of vacuum, comprising - a housing delimiting the vacuum therapy unit to the outside, - a pump for generating a vacuum, with an inlet and an outlet , - a sound damper for the pump , with a housing forming a cavity, and with a sound-damping material , an inlet and an outlet , wherein the outlet of the pump is in fluidic communication with the inlet of the sound damper , and the outlet of the sound damper is in fluidic communication with the atmosphere surrounding the vacuum therapy unit , and wherein the pump and the sound damper are located inside the housing of the vacuum therapy unit , characterized in that the housing of the sound damper comprises a hollow body in the form of a right prism with a base surface , a top surface and a lateral surface , wherein - the base surface of the prism is formed on the basis of a right-angled triangle with a first cathetus , a second cathetus and an imaginary hypotenuse , wherein the base surface has a stairway-like gradation along the imaginary hypotenuse , and wherein the portions of the base surface that form the stairway-like gradation extend either parallel or at a right angle to the first or the second cathetus , such that the lateral surface of the prism has a non-stepped first side face and a non-stepped second side face and a stepped third side face , wherein - one or more partition walls , which extend parallel to the first side face of the prism and along an edge of the third side face of the prism , are arranged in the cavity of the prism, such that the sound damper has substantially cuboid, mutually adjoining filter chambers of different size. - a housing delimiting the vacuum therapy unit to the outside, - a pump for generating a vacuum, with an inlet and an outlet , - a sound damper for the pump , with a housing forming a cavity, and with a sound-damping material , an inlet and an outlet , wherein the outlet of the pump is in fluidic communication with the inlet of the sound damper , and the outlet of the sound damper is in fluidic communication with the atmosphere surrounding the vacuum therapy unit , and wherein the pump and the sound damper are located inside the housing of the vacuum therapy unit , characterized in that the housing of the sound damper comprises a hollow body in the form of a right prism with a base surface , a top surface and a lateral surface , wherein - the base surface of the prism is formed on the basis of a right-angled triangle with a first cathetus , a second cathetus and an imaginary hypotenuse , wherein the base surface has a stairway-like gradation along the imaginary hypotenuse , and wherein the portions of the base surface that form the stairway-like gradation extend either parallel or at a right angle to the first or the second cathetus , such that the lateral surface of the prism has a non-stepped first side face and a non-stepped second side face and a stepped third side face , wherein - one or more partition walls , which extend parallel to the first side face of the prism and along an edge of the third side face of the prism , are arranged in the cavity of the prism, such that the sound damper has substantially cuboid, mutually adjoining filter chambers of different size. <EOS>