49 CFR § 210.7
Responsibility for noise defective railroad equipment
November 18, 2020
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.