[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: 49CFR227.111]

[Page 392-393]
 
                        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.  227.111  Audiometric test requirements.

    (a) Audiometric tests shall be pure tone, air conduction, hearing 
threshold examinations, with test frequencies including 500, 1000, 2000, 
3000, 4000, 6000, and 8000 Hz. Tests at each frequency shall be taken 
separately for each ear.
    (b) Audiometric tests shall be conducted with audiometers (including 
microprocessor audiometers) that meet the specifications of and are 
maintained and used in accordance with ANSI S3.6-2004 ``Specification 
for Audiometers.'' The Director of the Federal Register approves the 
incorporation by reference of this standard in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. You may obtain a copy of the incorporated 
standard from the American National Standards Institute at 1819 L 
Street, NW., Washington, DC 20036 or http://www.ansi.org. You may 
inspect a copy of the incorporated standard at the Federal Railroad 
Administration, Docket Room, 1120 Vermont Ave., NW., Suite 700, 
Washington, DC 20005, or at the National Archives and Records 
Administration (NARA). For more information on the availability of this 
material at NARA, call 202-741-6030, or go to http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
    (1) Pulsed-tone audiometers should be used with the following on and 
off times: F-J and J-K shall each have values of 225  35 milliseconds (ms).
    (2) Use of insert earphones shall be consistent with the 
requirements listed in appendix E of this part: Use of Insert Earphones 
for Audiometric Testing.
    (c) Audiometric examinations shall be administered in a room meeting 
the requirements listed in appendix D of this part: Audiometric Test 
Rooms.
    (d) Audiometer calibration.
    (1) The functional operation of the audiometer shall be checked 
before each day's use by testing a person with known, stable hearing 
thresholds or by appropriate calibration device, and by listening to the 
audiometer's output to make sure that the output is free from distorted 
or unwanted sounds. Deviations of 10 decibels or greater require an 
acoustic calibration.

[[Page 393]]

    (2) Audiometer calibration shall be checked acoustically at least 
annually according to the procedures described in ANSI S3.6-2004. 
Frequencies below 500 Hz and above 8000 Hz may be omitted from this 
check. The audiometer must meet the sound pressure accuracy requirements 
of section 7.2 of ANSI S3.6-2004 of 3 dB at any test frequency between 
500 and 5000 Hz and 5 dB at any test frequency 6000 Hz and higher for 
the specific type of transducer used. For air-conduction supra-aural 
earphones, the specifications in Table 6 of ANSI S3.6-2004 shall apply. 
For air-conduction insert earphones, the specifications in Table 7 of 
ANSI S3.6-2004 shall apply. Audiometers that do not meet these 
requirements must undergo an exhaustive calibration.
    (3) Exhaustive Calibration. An exhaustive calibration shall be 
performed in accordance with ANSI S3.6-2004, according to the following 
schedule:
    (i) At least once every two years on audiometers not used in mobile 
test vans. Test frequencies below 500 Hz and above 6000 Hz may be 
omitted from this calibration.
    (ii) At least annually on audiometers used in mobile test vans.