49 C.F.R. § 210.7 – Responsibility for noise defective railroad equipment.

Any railroad that uses railroad equipment that is noise defective or engages in a car coupling operating that results in excessive noise according to the criteria established in this part and in the Standards is responsible for compliance with this part. Subject to § 210.9, such railroad shall—

(a) Correct the noise defect;
(b) Remove the noise defective railroad equipment from service; or
(c) Modify the car coupling procedure to bring it within the prescribed noise limits.