[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR227.117] [Page 393-394] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 227_OCCUPATIONAL NOISE EXPOSURE--Table of Contents Subpart B_Occupational Noise Exposure for Railroad Operating Employees. Sec. 227.117 Hearing protector attenuation. (a) A railroad shall evaluate hearing protector attenuation for the specific noise environments in which the protector will be used. The railroad shall use one of the evaluation methods described in appendix B of this part; ``Methods for Estimating the Adequacy of Hearing Protector Attenuation.'' (b) Hearing protectors shall attenuate employee exposure to an 8- hour TWA of 90 decibels or lower, as required by Sec. 227.115. (c) For employees who have experienced a standard threshold shift, hearing protectors must attenuate employee exposure to an 8-hour time- weighted average of 85 decibels or lower. (d) The adequacy of hearing protector attenuation shall be re- evaluated whenever employee noise exposures increase to the extent that the hearing [[Page 394]] protectors provided may no longer provide adequate attenuation. A railroad shall provide more effective hearing protectors where necessary.