OSHA general industry occupational noise exposure study guide
29 CFR 1910.95 is OSHA's general industry rule on occupational noise exposure. This guide sets out what the rule text states on the permissible exposures in Table G-16, feasible controls, the hearing conservation program that starts at an 8-hour time-weighted average of 85 decibels, noise monitoring, audiometric testing, standard threshold shifts and follow-up, hearing protectors and their attenuation, training, access to information, recordkeeping and the appendices. American National Standards the rule incorporates (such as S3.6-1969) are only named here, not summarized. Every point links to the regulation and quotes its exact words.
Permissible exposures and controls
Protection against the effects of noise must be provided when sound levels exceed those shown in Table G-16, measured on the A scale of a standard sound level meter at slow response.
“Protection against the effects of noise exposure shall be provided when the sound levels exceed those shown in Table G-16 when measured on the A scale of a standard sound level meter at slow response.”
Table G-16 (Permissible noise exposures) pairs a duration per day with a sound level in dBA, slow response: 8 hours at 90, 6 hours at 92, 4 hours at 95, 3 hours at 97 and 2 hours at 100.
“Duration per day, hours Sound level dBA slow response 8 90 6 92 4 95 3 97 2 100”
Table G-16's footnote: if the sum of the fractions C1/T1 + C2/T2 ... Cn/Tn exceeds unity, the mixed exposure should be considered to exceed the limit value. Cn is the total time of exposure at a specified noise level and Tn the total time of exposure permitted at that level.
“If the sum of the following fractions: C1/T1 + C2/T2 C n/T n exceeds unity, then, the mixed exposure should be considered to exceed the limit value. Cn indicates the total time of exposure at a specified noise level, and Tn indicates the total time of exposure permitted at that level.”
Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.
“Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.”
When employees are subjected to sound exceeding Table G-16, feasible administrative or engineering controls must be used. If those controls fail to bring sound levels within the table, personal protective equipment must be provided and used to do so.
“When employees are subjected to sound exceeding those listed in Table G-16, feasible administrative or engineering controls shall be utilized. If such controls fail to reduce sound levels within the levels of Table G-16, personal protective equipment shall be provided and used to reduce sound levels within the levels of the table.”
Not covered here
Reading octave band levels off Figure G-9 (the equivalent sound level contour graph). The graph is an image and is not in the text this guide is built from. The Table G-16 rows below 2 hours (1 1/2 hours, 1 hour, 1/2 hour and 1/4 hour or less) are not listed here because the fractions in that part of the table do not come through cleanly in the text copy; read them in the linked table. We only write what an official source states, so study these parts with your certifying program's materials.
Hearing conservation program
The employer must run a continuing, effective hearing conservation program whenever employee noise exposures equal or exceed an 8-hour time-weighted average sound level (TWA) of 85 decibels on the A scale (slow response), or equivalently a dose of fifty percent.
“The employer shall administer a continuing, effective hearing conservation program, as described in paragraphs (c) through (o) of this section, whenever employee noise exposures equal or exceed an 8-hour time-weighted average sound level (TWA) of 85 decibels measured on the A scale (slow response) or, equivalently, a dose of fifty percent.”
For the hearing conservation program, exposures are computed under Appendix A and Table G-16a, without regard to any attenuation from personal protective equipment.
“employee noise exposures shall be computed in accordance with appendix A and Table G-16a, and without regard to any attenuation provided by the use of personal protective equipment.”
For paragraphs (c) through (n), an 8-hour TWA of 85 decibels or a dose of fifty percent is called the action level.
“For purposes of paragraphs (c) through (n) of this section, an 8-hour time-weighted average of 85 decibels or a dose of fifty percent shall also be referred to as the action level.”
Paragraphs (c) through (n) of the section do not apply to employers engaged in oil and gas well drilling and servicing operations.
“Paragraphs (c) through (n) of this section shall not apply to employers engaged in oil and gas well drilling and servicing operations.”
Noise monitoring
When information indicates that any employee's exposure may equal or exceed an 8-hour TWA of 85 decibels, the employer must develop and implement a monitoring program.
“When information indicates that any employee's exposure may equal or exceed an 8-hour time-weighted average of 85 decibels, the employer shall develop and implement a monitoring program.”
Where circumstances such as high worker mobility, significant variations in sound level, or a significant component of impulse noise make area monitoring generally inappropriate, the employer must use representative personal sampling, unless it can show that area sampling produces equivalent results.
“Where circumstances such as high worker mobility, significant variations in sound level, or a significant component of impulse noise make area monitoring generally inappropriate, the employer shall use representative personal sampling to comply with the monitoring requirements of this paragraph unless the employer can show that area sampling produces equivalent results.”
All continuous, intermittent and impulsive sound levels from 80 decibels to 130 decibels must be integrated into the noise measurements.
“All continuous, intermittent and impulsive sound levels from 80 decibels to 130 decibels shall be integrated into the noise measurements.”
Instruments used to measure employee noise exposure must be calibrated to ensure measurement accuracy.
“Instruments used to measure employee noise exposure shall be calibrated to ensure measurement accuracy.”
Monitoring must be repeated whenever a change in production, process, equipment or controls increases noise exposures so that additional employees may be exposed at or above the action level, or the attenuation of the hearing protectors in use may become inadequate under paragraph (j).
“Monitoring shall be repeated whenever a change in production, process, equipment or controls increases noise exposures to the extent that: (i) Additional employees may be exposed at or above the action level; or (ii) The attenuation provided by hearing protectors being used by employees may be rendered inadequate to meet the requirements of paragraph (j) of this section.”
The employer must notify each employee exposed at or above an 8-hour TWA of 85 decibels of the monitoring results.
“The employer shall notify each employee exposed at or above an 8-hour time-weighted average of 85 decibels of the results of the monitoring.”
Appendix G (Monitoring Noise Levels), a non-mandatory informational appendix, says area monitoring can be used to estimate noise exposure when the noise levels are relatively constant and employees are not mobile.
“Area monitoring can be used to estimate noise exposure when the noise levels are relatively constant and employees are not mobile.”
Audiometric testing
The employer must make audiometric testing available to all employees whose exposures equal or exceed an 8-hour TWA of 85 decibels, and the program must be provided at no cost to employees.
“The employer shall establish and maintain an audiometric testing program as provided in this paragraph by making audiometric testing available to all employees whose exposures equal or exceed an 8-hour time-weighted average of 85 decibels. (2) The program shall be provided at no cost to employees.”
Audiometric tests must be performed by a licensed or certified audiologist, otolaryngologist or other physician, or by a technician who is certified by the Council of Accreditation in Occupational Hearing Conservation or who has satisfactorily demonstrated competence in administering audiometric examinations, obtaining valid audiograms, and properly using, maintaining and checking calibration and proper functioning of the audiometers being used.
“Audiometric tests shall be performed by a licensed or certified audiologist, otolaryngologist, or other physician, or by a technician who is certified by the Council of Accreditation in Occupational Hearing Conservation, or who has satisfactorily demonstrated competence in administering audiometric examinations, obtaining valid audiograms, and properly using, maintaining and checking calibration and proper functioning of the audiometers being used.”
A technician who operates microprocessor audiometers does not need to be certified. A technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician.
“A technician who operates microprocessor audiometers does not need to be certified. A technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician.”
A valid baseline audiogram must be established within 6 months of an employee's first exposure at or above the action level.
“Within 6 months of an employee's first exposure at or above the action level, the employer shall establish a valid baseline audiogram against which subsequent audiograms can be compared.”
Mobile test van exception: where mobile test vans are used, the baseline must be obtained within 1 year of first exposure at or above the action level. If the baseline comes more than 6 months after first exposure, the employee must wear hearing protectors for any period exceeding six months after first exposure until the baseline is obtained.
“Where mobile test vans are used to meet the audiometric testing obligation, the employer shall obtain a valid baseline audiogram within 1 year of an employee's first exposure at or above the action level. Where baseline audiograms are obtained more than 6 months after the employee's first exposure at or above the action level, employees shall wearing hearing protectors for any period exceeding six months after first exposure until the baseline audiogram is obtained.”
Testing to establish a baseline audiogram must be preceded by at least 14 hours without exposure to workplace noise; hearing protectors may be used as a substitute for that requirement.
“Testing to establish a baseline audiogram shall be preceded by at least 14 hours without exposure to workplace noise. Hearing protectors may be used as a substitute for the requirement that baseline audiograms be preceded by 14 hours without exposure to workplace noise.”
The employer must notify employees of the need to avoid high levels of non-occupational noise exposure during the 14-hour period immediately preceding the audiometric examination.
“The employer shall notify employees of the need to avoid high levels of non-occupational noise exposure during the 14-hour period immediately preceding the audiometric examination.”
At least annually after the baseline, the employer must obtain a new audiogram for each employee exposed at or above an 8-hour TWA of 85 decibels.
“At least annually after obtaining the baseline audiogram, the employer shall obtain a new audiogram for each employee exposed at or above an 8-hour time-weighted average of 85 decibels.”
The audiometer's functional operation must be checked before each day's use; deviations of 10 decibels or greater require an acoustic calibration.
“The functional operation of the audiometer shall be checked before each day's use by testing a person with known, stable hearing thresholds, 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.”
Audiometer calibration must be checked acoustically at least annually under Appendix E (test frequencies below 500 Hz and above 6000 Hz may be omitted); deviations of 15 decibels or greater require an exhaustive calibration.
“Audiometer calibration shall be checked acoustically at least annually in accordance with appendix E: Acoustic Calibration of Audiometers. Test frequencies below 500 Hz and above 6000 Hz may be omitted from this check. Deviations of 15 decibels or greater require an exhaustive calibration.”
An exhaustive calibration must be performed at least every two years, under listed sections of American National Standard S3.6-1969; test frequencies below 500 Hz and above 6000 Hz may be omitted from it.
“An exhaustive calibration shall be performed at least every two years in accordance with sections 4.1.2; 4.1.3.; 4.1.4.3; 4.2; 4.4.1; 4.4.2; 4.4.3; and 4.5 of the American National Standard Specification for Audiometers, S3.6-1969. Test frequencies below 500 Hz and above 6000 Hz may be omitted from this calibration.”
Not covered here
The audiometer specifications of American National Standard S3.6-1969, which the rule incorporates by reference. They are only named here. We only write what an official source states, so study these parts with your certifying program's materials.
Standard threshold shift and follow-up
A standard threshold shift is a change in hearing threshold, relative to the baseline audiogram, of an average of 10 dB or more at 2000, 3000 and 4000 Hz in either ear.
“a standard threshold shift is a change in hearing threshold relative to the baseline audiogram of an average of 10 dB or more at 2000, 3000, and 4000 Hz in either ear.”
If the annual audiogram shows a standard threshold shift, the employer may obtain a retest within 30 days and treat the retest as the annual audiogram.
“the employer may obtain a retest within 30 days and consider the results of the retest as the annual audiogram.”
When a standard threshold shift has occurred, the employee must be informed in writing within 21 days of the determination.
“the employee shall be informed of this fact in writing, within 21 days of the determination.”
Unless a physician determines that the standard threshold shift is not work related or aggravated by occupational noise exposure, employees not using hearing protectors must be fitted with them, trained in their use and care, and required to use them.
“Unless a physician determines that the standard threshold shift is not work related or aggravated by occupational noise exposure, the employer shall ensure that the following steps are taken when a standard threshold shift occurs: (A) Employees not using hearing protectors shall be fitted with hearing protectors, trained in their use and care, and required to use them.”
The same follow-up steps: employees already using hearing protectors must be refitted and retrained and given protectors with greater attenuation if necessary, and the employee must be referred for a clinical audiological evaluation or an otological examination, as appropriate, if more testing is necessary or the employer suspects a medical pathology of the ear caused or aggravated by wearing hearing protectors.
“Employees already using hearing protectors shall be refitted and retrained in the use of hearing protectors and provided with hearing protectors offering greater attenuation if necessary. (C) The employee shall be referred for a clinical audiological evaluation or an otological examination, as appropriate, if additional testing is necessary or if the employer suspects that a medical pathology of the ear is caused or aggravated by the wearing of hearing protectors.”
If later testing of an employee whose exposure is less than an 8-hour TWA of 90 decibels shows the shift is not persistent, the employer must inform the employee of the new interpretation and may discontinue the required use of hearing protectors for that employee.
“If subsequent audiometric testing of an employee whose exposure to noise is less than an 8-hour TWA of 90 decibels indicates that a standard threshold shift is not persistent, the employer: (A) Shall inform the employee of the new audiometric interpretation; and (B) May discontinue the required use of hearing protectors for that employee.”
An annual audiogram may be substituted for the baseline when, in the judgment of the evaluating audiologist, otolaryngologist or physician, the standard threshold shift is persistent, or the annual audiogram shows significant improvement over the baseline.
“An annual audiogram may be substituted for the baseline audiogram when, in the judgment of the audiologist, otolaryngologist or physician who is evaluating the audiogram: (i) The standard threshold shift revealed by the audiogram is persistent; or (ii) The hearing threshold shown in the annual audiogram indicates significant improvement over the baseline audiogram.”
Appendix F (Calculations and Application of Age Corrections to Audiograms) is labeled non-mandatory. It says that, in determining whether a standard threshold shift has occurred, allowance may be made for aging by adjusting the most recent audiogram, and that an employer that chooses to adjust the audiogram must follow its procedure.
“This appendix Is Non-Mandatory In determining whether a standard threshold shift has occurred, allowance may be made for the contribution of aging to the change in hearing level by adjusting the most recent audiogram. If the employer chooses to adjust the audiogram, the employer shall follow the procedure described below.”
Not covered here
Recording a hearing loss case on the OSHA 300 log. That is in 29 CFR Part 1904, not in 1910.95. We only write what an official source states, so study these parts with your certifying program's materials.
Hearing protectors
Hearing protectors must be made available, at no cost, to all employees exposed to an 8-hour TWA of 85 decibels or greater, and replaced as necessary.
“Employers shall make hearing protectors available to all employees exposed to an 8-hour time-weighted average of 85 decibels or greater at no cost to the employees. Hearing protectors shall be replaced as necessary.”
Hearing protectors must be worn by an employee required by paragraph (b)(1) to wear PPE, and by any employee exposed to an 8-hour TWA of 85 decibels or greater who has not yet had a baseline audiogram under (g)(5)(ii) or has experienced a standard threshold shift.
“Employers shall ensure that hearing protectors are worn: (i) By an employee who is required by paragraph (b)(1) of this section to wear personal protective equipment; and (ii) By any employee who is exposed to an 8-hour time-weighted average of 85 decibels or greater, and who: (A) Has not yet had a baseline audiogram established pursuant to paragraph (g)(5)(ii); or (B) Has experienced a standard threshold shift.”
Employees must be given the opportunity to select their hearing protectors from a variety of suitable protectors provided by the employer.
“Employees shall be given the opportunity to select their hearing protectors from a variety of suitable hearing protectors provided by the employer.”
The employer must train employees in the use and care of all hearing protectors provided, ensure proper initial fitting, and supervise correct use.
“The employer shall provide training in the use and care of all hearing protectors provided to employees. (5) The employer shall ensure proper initial fitting and supervise the correct use of all hearing protectors.”
Hearing protectors must attenuate employee exposure at least to an 8-hour TWA of 90 decibels, as required by paragraph (b). For employees who have experienced a standard threshold shift, they must attenuate exposure to an 8-hour TWA of 85 decibels or below.
“Hearing protectors must attenuate employee exposure at least to an 8-hour time-weighted average of 90 decibels as required by paragraph (b) of this section. (3) 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 below.”
Appendix B (mandatory) sets out methods for estimating the adequacy of hearing protector attenuation. One of its Noise Reduction Rating (NRR) methods, when using a sound level meter set to the A-weighting network: obtain the employee's A-weighted TWA, subtract 7 dB from the NRR, and subtract the remainder from the A-weighted TWA to obtain the estimated A-weighted TWA under the ear protector.
“When using a sound level meter set to the A-weighting network: (A) Obtain the employee's A-weighted TWA. (B) Subtract 7 dB from the NRR, and subtract the remainder from the A-weighted TWA to obtain the estimated A-weighted TWA under the ear protector.”
Training, information and records
Training must be repeated annually for each employee in the hearing conservation program, and its information updated to match changes in protective equipment and work processes.
“The training program shall be repeated annually for each employee included in the hearing conservation program. Information provided in the training program shall be updated to be consistent with changes in protective equipment and work processes.”
Each employee must be informed of the effects of noise on hearing; the purpose, advantages, disadvantages and attenuation of various types of hearing protectors, with instructions on selection, fitting, use and care; and the purpose of audiometric testing with an explanation of the test procedures.
“The employer shall ensure that each employee is informed of the following: (i) The effects of noise on hearing; (ii) The purpose of hearing protectors, the advantages, disadvantages, and attenuation of various types, and instructions on selection, fitting, use, and care; and (iii) The purpose of audiometric testing, and an explanation of the test procedures.”
Copies of the standard must be made available to affected employees or their representatives, and a copy must be posted in the workplace.
“The employer shall make available to affected employees or their representatives copies of this standard and shall also post a copy in the workplace.”
Audiometric test records must include the employee's name and job classification, the date of the audiogram, the examiner's name, the date of the last acoustic or exhaustive calibration of the audiometer, and the employee's most recent noise exposure assessment. The employer must also keep accurate records of the background sound pressure level measurements in audiometric test rooms.
“This record shall include: (A) Name and job classification of the employee; (B) Date of the audiogram; (C) The examiner's name; (D) Date of the last acoustic or exhaustive calibration of the audiometer; and (E) Employee's most recent noise exposure assessment. (F) The employer shall maintain accurate records of the measurements of the background sound pressure levels in audiometric test rooms.”
Records must be kept for at least these periods: noise exposure measurement records for two years, and audiometric test records for the duration of the affected employee's employment.
“The employer shall retain records required in this paragraph (m) for at least the following periods. (i) Noise exposure measurement records shall be retained for two years. (ii) Audiometric test records shall be retained for the duration of the affected employee's employment.”
All records required by the section must be provided on request to employees, former employees, representatives designated by the individual employee, and the Assistant Secretary.
“All records required by this section shall be provided upon request to employees, former employees, representatives designated by the individual employee, and the Assistant Secretary.”
If the employer ceases to do business, it must transfer all records required by the section to the successor employer, which must keep them for the remainder of the period prescribed in paragraph (m)(3).
“If the employer ceases to do business, the employer shall transfer to the successor employer all records required to be maintained by this section, and the successor employer shall retain them for the remainder of the period prescribed in paragraph (m)(3) of this section.”
Appendices
Appendices A, B, C, D and E are incorporated as part of the section and their contents are mandatory. Appendices F and G are informational and are not intended to create additional obligations or to detract from existing ones.
“Appendices A, B, C, D, and E to this section are incorporated as part of this section and the contents of these appendices are mandatory. (2) Appendices F and G to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations.”
Appendix A (Noise Exposure Computation, mandatory): when the sound level is constant over the entire work shift, the dose in percent is D = 100 C/T, where C is the total length of the work day in hours and T is the reference duration for the measured sound level as given in Table G-16a.
“When the sound level, L, is constant over the entire work shift, the noise dose, D, in percent, is given by: D = 100 C/T where C is the total length of the work day, in hours, and T is the reference duration corresponding to the measured sound level, L, as given in Table G-16a”
Under Appendix A, the TWA may be computed from the dose with TWA = 16.61 log10 (D/100) + 90. For an eight-hour shift with the noise level constant over the entire shift, the TWA equals the measured sound level.
“The eight-hour time-weighted average sound level (TWA), in decibels, may be computed from the dose, in percent, by means of the formula: TWA = 16.61 log10 (D/100) + 90. For an eight-hour workshift with the noise level constant over the entire shift, the TWA is equal to the measured sound level.”
Appendix A's worked example: a dose of 91 percent over an eight hour day gives a TWA of 89.3 dB, and a dose of 50 percent corresponds to a TWA of 85 dB.
“a dose of 91 percent over an eight hour day results in a TWA of 89.3 dB, and, a dose of 50 percent corresponds to a TWA of 85 dB.”
Appendix D (Audiometric Test Rooms, mandatory): Table D-1 lists the maximum allowable octave-band sound pressure levels for audiometric test rooms: 40 dB at 500 Hz, 40 dB at 1000 Hz, 47 dB at 2000 Hz, 57 dB at 4000 Hz and 62 dB at 8000 Hz.
“TABLE D-1—MAXIMUM ALLOWABLE OCTAVE-BAND SOUND PRESSURE LEVELS FOR AUDIOMETRIC TEST ROOMS Octave-band center frequency (Hz) 500 1000 2000 4000 8000 Sound pressure level (dB) 40 40 47 57 62”
Not covered here
The age correction tables of Appendix F and the acoustic calibration tables of Appendix E. Appendix H (availability of referenced documents), which lists the publications the rule incorporates by reference and where they are available. We only write what an official source states, so study these parts with your certifying program's materials.
Sources
- eCFR: 29 CFR 1910.95, Occupational noise exposure (as of Nov 3, 2026)Checked November 5, 2026
Other OSHA General Industry study guides: Walking-working surfaces, Exit routes and emergency planning, Fire protection, Electrical safety, Personal protective equipment, Hazardous materials, Permit-required confined spaces, Lockout/tagout, Machine guarding, Welding, cutting and brazing, Electric power generation, transmission and distribution, Powered industrial trucks (forklifts), Materials handling and storage, Bloodborne pathogens