Apparatus for measuring volumes of sounds from a road vehicle in road traffic, the apparatus comprising • an acoustic sensor, • a protective grille for protecting the apparatus from the ingress of coarser foreign bodies, the protective grille comprising at least one opening (3a, 3b, 3c, 3d) for admitting airborne sound to the apparatus, the opening (3a, 3b, 3c, 3d) being arranged in a manner axially offset from an axial axis of the apparatus, • a printed circuit board, the printed circuit board comprising ∘ elements and the connections therebetween for preprocessing analogue or digital signals from the acoustic sensor, the elements being designed for analogue or digital signal processing and/or to perform filter functions, phase inversion functions, compressor functions and/or amplifier functions, ∘ a computing unit designed to take signals from the acoustic sensor as a basis for generating a control signal for a capture unit when it has been identified that a setpoint volume has been exceeded, in order to capture the road vehicle, and • an interface in order to provide the control signal to the capture unit, characterized in that the apparatus further comprises: • a flow bypass, running between the protective grille and the acoustic sensor, in order to route fluids and/or foreign bodies that have entered the apparatus by way of airflows away from the acoustic sensor out of the apparatus, and • a sound channel, at whose one first end in the airflow direction the protective grille is arranged and at whose second end the acoustic sensor is arranged, the diameter, length, volume, shaping and/or material properties of the sound channel being adapted to damp eigenmodes of the apparatus, wherein the printed circuit board further comprises a printed circuit board opening, on whose rear side of the printed circuit board in the airflow direction the acoustic sensor is arranged. • an acoustic sensor, • a protective grille for protecting the apparatus from the ingress of coarser foreign bodies, the protective grille comprising at least one opening (3a, 3b, 3c, 3d) for admitting airborne sound to the apparatus, the opening (3a, 3b, 3c, 3d) being arranged in a manner axially offset from an axial axis of the apparatus, • a printed circuit board, the printed circuit board comprising ∘ elements and the connections therebetween for preprocessing analogue or digital signals from the acoustic sensor, the elements being designed for analogue or digital signal processing and/or to perform filter functions, phase inversion functions, compressor functions and/or amplifier functions, ∘ a computing unit designed to take signals from the acoustic sensor as a basis for generating a control signal for a capture unit when it has been identified that a setpoint volume has been exceeded, in order to capture the road vehicle, and ∘ elements and the connections therebetween for preprocessing analogue or digital signals from the acoustic sensor, the elements being designed for analogue or digital signal processing and/or to perform filter functions, phase inversion functions, compressor functions and/or amplifier functions, ∘ a computing unit designed to take signals from the acoustic sensor as a basis for generating a control signal for a capture unit when it has been identified that a setpoint volume has been exceeded, in order to capture the road vehicle, and • an interface in order to provide the control signal to the capture unit, • a flow bypass, running between the protective grille and the acoustic sensor, in order to route fluids and/or foreign bodies that have entered the apparatus by way of airflows away from the acoustic sensor out of the apparatus, and • a sound channel, at whose one first end in the airflow direction the protective grille is arranged and at whose second end the acoustic sensor is arranged, the diameter, length, volume, shaping and/or material properties of the sound channel being adapted to damp eigenmodes of the apparatus,