A-weighted. An adjustment to sound level measurements that reflects the sensitivity of the human ear. Used for evaluating continuous or average noise levels.

Audiogram. A chart, graph, or table resulting from an audiometric test showing an individual's hearing threshold levels as a function of frequency.

Audiologist. A professional, specializing in the study and rehabilitation of hearing, who is certified by the American Speech, Hearing, and Language Association, or the American Academy of Audiology, and is licensed by the state board of examiners.

Baseline audiogram. The audiogram against which future audiograms are compared. The baseline audiogram is collected when an employee is first assigned to work with noise exposure. The baseline audiogram may be revised if persistent standard threshold shift (STS) of improvement is found.

Continuous noise. Noise with peaks spaced no more than one second apart. Continuous noise is measured using sound level meters and noise dosimeters with the slow response setting.

Criterion sound level. A sound level of ninety decibels. An eight-hour exposure to constant 90 dBA noise is a one hundred percent noise dose exposure.

C-weighted. An adjustment to sound level measurements that evenly represents frequencies within the range of human hearing. Used for evaluating impact or impulse noise.

Decibel (dB). Unit of measurement of sound level. A-weighting, adjusting for the sensitivity of the human ear, is indicated as "dBA." C-weighting, an even reading across the frequencies of human hearing, is indicated as "dBC."

Fast response. A setting for a sound level meter that will allow the meter to respond to noise events of less than one second. Used for evaluating impulse and impact noise levels.

Hertz (Hz). Unit of measurement of frequency, numerically equal to cycles per second.

Impulsive or impact noise. Noise levels which involve maxima at intervals greater than one second. Impulse and impact noise are measured using the fast response setting on a sound level meter.

Noise dose. The total noise exposure received by an employee during their shift. It can be expressed as a percentage indicating the ratio of exposure received to the noise exposure received in an eight-hour exposure to constant noise at 90 dBA. It may also be expressed as the sound level that would produce the equivalent exposure during an eight-hour period (TWA8).

Noise dosimeter. An instrument that integrates a function of sound pressure over a period of time in such a manner that it directly indicates a noise dose.

Occupational hearing loss. A reduction in the ability of an individual to hear either caused or contributed to by exposure in the work environment.

Otolaryngologist. A physician specializing in diagnosis and treatment of disorders of the ear, nose, and throat.

Permanent threshold shift. A hearing level change that has become persistent and is not expected to improve.

Qualified reviewer. An audiologist, otolaryngologist, or other qualified physician who has experience and training in evaluating occupational audiograms.

Slow response. A setting for sound level meters and dosimeters in which the meter does not register events of less than about one second. Used for evaluating continuous and average noise levels.

Sound level. The intensity of noise as indicated by a sound level meter.

Sound level meter. An instrument that measures sound levels.

Standard threshold shift (STS). A hearing level change, relative to the baseline audiogram, of an average of 10 dB or more at 2000, 3000, and 4000 Hz in either ear.

Temporary threshold shift. A hearing level change that improves. A temporary threshold shift may occur with exposure to noise and hearing will return to normal within a few days. Temporary threshold shifts can be indicators of exposures that lead to permanent hearing loss.

TWA8 - Equivalent eight-hour time-weighted average sound level. That sound level, which if constant over an eight-hour period, would result in the same noise dose measured in an environment where the noise level varies.

The purpose of this chapter is to:

(1) Prevent employee hearing loss by minimizing employee noise exposures; and

(2) Make sure employees exposed to noise are protected.

These goals are accomplished by:

(1) Measuring and computing the employee noise exposure from all equipment and machinery in the workplace, as well as any other noise sources in the work area;

(2) Protecting employees from noise exposure by using feasible noise controls;

(3) Making sure employees use hearing protection, if you cannot feasibly control the noise;

(4) Training employees about hearing loss prevention;

(5) Evaluating your hearing loss prevention efforts by tracking employee hearing or periodically reviewing controls and protection;

(6) Making appropriate corrections to your program.

Use Table 1 to help you determine the hearing loss prevention requirements for your workplace:

To prevent employee hearing loss by minimizing, and providing protection from, noise exposures.

(1) You must conduct employee noise exposure monitoring to determine the employee's actual exposure when reasonable information indicates that any employee's exposure may equal or exceed 85 dBA TWA8.

(2) You must follow applicable guidance in WAC 296-817-300 when conducting noise exposure monitoring;

(3) You must make sure your sampling for noise exposure monitoring identifies:

(a) All employees whose exposure equals or exceeds the following:

(i) 85 dBA TWA8 (noise dosimetry, providing an average exposure over an eight-hour time period);

(ii) 115 dBA (slow response sound level meter, identifying short-term noise exposures);

(iii) 140 dBC (fast response sound level meter, identifying almost instantaneous noise exposures).

(b) Exposure levels for selection of hearing protection.

(4) You must provide exposed employees and their representatives with an opportunity to observe any measurements of employee noise exposure that are conducted.

(5) You must notify each employee whose exposure equals or exceeds 85 dBA TWA8 of the monitoring results within five working days of when you receive the results.

(6) You must conduct additional noise monitoring whenever a change in production, process, equipment or controls, may reasonably be expected to result in:

(a) Additional employees whose exposure equals or exceeds 85 dBA TWA8;

(b) Employees exposed to higher level of noise requiring more effective hearing protection.

Hearing protection provides a barrier to noise and protects employees but is not considered a control of the noise hazard. Separate requirements apply to hearing protection and are found in WAC 296-817-20015.

You must reduce employee noise exposure, using feasible controls, wherever exposure equals or exceeds 90 dBA TWA8.

(1) You must make sure employees wear hearing protectors that will provide sufficient protection when exposure equals or exceeds:

(a) 85 dBA TWA8 (noise dosimetry, providing an average exposure over an eight-hour time period);

(b) 115 dBA (slow response sound level meter, identifying short-term noise exposures);

(c) 140 dBC (fast response sound level meter, identifying almost instantaneous noise exposures).

(2) You must provide employees with an appropriate selection of hearing protectors:

(a) The selection must include at least two distinct types (such as molded earplugs, foam earplugs, custom-molded earplugs, earcaps, or earmuffs) for each exposed employee and must be sufficient to cover:

(i) Different levels of hearing protection needed in order to reduce all employee exposures to a level below 85 dBA TWA8;

(ii) Different sizes;

(iii) Different working conditions.

(b) Consider requests of the employees regarding:

(i) Physical comfort;

(ii) Environmental conditions;

(iii) Medical needs;

(iv) Communication requirements.

(3) You must provide hearing protection at no cost to employees.

(4) You must supervise employees to make sure that hearing protection is used correctly.

(5) You must make sure hearing protectors are:

(a) Properly chosen for fit;

(b) Replaced as necessary.

(6) You must make sure all hearing protection is sufficient to reduce the employee's equivalent eight-hour noise exposure to 85 dBA or less. When using the A-weighted exposure measurements, reported as "dBA TWA8," the reduction in noise exposure by hearing protectors is given by Table 2:

(7) In addition to protection based on daily noise dose, make sure hearing protection has an NRR of at least 20 dB when exposures involve noise that equals or exceeds 115 dBA (slow response sound level meter) or 140 dBC (fast response sound level meter).

(1) You must train each employee whose noise exposure equals or exceeds 85 dBA TWA8.

(2) You must provide training when an employee is first assigned to a position involving noise exposure that equals or exceeds 85 dBA TWA8and at least annually after that.

(3) You must update information provided in the training program to be consistent with changes in controls, hearing protectors and work processes.

(4) You must make sure your noise and hearing protection training includes:

(a) The effects of noise on hearing (including both occupational and nonoccupational exposures);

(b) Noise controls used in your workplace;

(c) The purpose of hearing protectors: The advantages, disadvantages, and attenuation of various types;

(d) Instructions about selecting, fitting, using, and caring for hearing protection;

(e) The purpose and procedures for program evaluation including audiometric testing and hearing protection auditing when you choose to rely upon auditing (see WAC 296-817-500);

(f) The employees' right to access records kept by the employer.

(5) You must maintain a written program describing initial and refresher training.

(1) You must make sure warning signs are posted at the entrances or boundaries of all well-defined work areas where employees may be exposed to noise that equals or exceeds 115 dBA (measured using a sound level meter with slow response).

(2) Warning signs must clearly indicate that the area is a high noise area and that hearing protectors are required.

(1) You must make sure audiometric testing as described by WAC 296-817-400 is supervised and reviewed by one of the following licensed or certified individuals:

(a) An audiologist;

(b) An otolaryngologist;

(c) Another qualified physician.

(2) You must make sure audiograms are conducted by one of the above individuals or by a technician certified by the Council of Accreditation in Occupational Hearing Conservation (CAOHC) and responsible to a qualified reviewer.

(1) You must use audiometric testing to identify hearing loss, which may indicate program deficiencies.

(2) You must take appropriate actions when deficiencies are found with your program.

A deficiency may be indicated when:

(a) Any employee experiences measurable hearing loss indicated by a standard threshold shift; or

(b) Any employee is not wearing appropriate hearing protection during an audit when auditing is used in place of baseline audiograms for short term employees (see WAC 296-817-500, Option to audiometric testing).

(3) You must evaluate the following, at a minimum, when responding to a standard threshold shift:

(a) Employee noise exposure measurements;

(b) Noise controls in the work area;

(c) The selection of hearing protection available and refit employees as necessary;

(d) Employee training on noise and the use of hearing protection and conduct additional training as necessary.

You must create and retain records documenting noise exposures. Include, at a minimum:

(1) Exposure measurements required by this chapter for at least two years and for as long as you rely upon them to determine employee exposure;

(2) Audiometric test records for the duration of employment for the affected employees;

(3) Hearing protection audits, if you choose to rely upon them, for the duration of employment of the affected employees.

Conduct noise monitoring or measurement to evaluate employee exposures in your workplace.

(1) You must make sure that noise dosimetry equipment meets these specifications:

(a) Dosimeters must be equipment class 2AS-90/80-5 of the American National Rule Specification for Personal Noise Dosimeters, ANSI S1.25-1991.

(b) Such dosimeters are normally marked "Type 2."

(2) You must make sure that sound level meters meet these specifications:

(a) American National Standard Specification for Sound Level Meters, S1.4-1984, Type 2 requirements for sound level meters.

(b) Such sound level meters are normally marked "Type 2."

(i) For continuous noise measurements, the meter must be capable of measuring A-weighted sound levels with slow response.

(ii) For impulse or impact noise measurements, the meter must be capable of indicating maximum C-weighted sound level measurements with fast response.

(3) Calibrate dosimeters and sound level meters used to monitor employee noise exposure:

(a) Before and after each day's use; and

(b) Following the instrument manufacturer's calibration instructions.

A noise dosimeter is the basis for determining total daily noise exposure for employees. However, where you have constant noise levels, you may estimate employee noise exposure using measurements from a sound level meter. Calculation of the employee noise exposure must be consistent with WAC 296-817-30015.

(1) You must include all:

(a) Workplace noise from equipment and machinery in use;

(b) Other noise from sources necessary to perform the work;

(c) Noise outside the control of the exposed employees.

(2) You must use a noise dosimeter when necessary to measure employee noise dose.

(3) You must use a sound level meter to evaluate continuous and impulse noise levels.

(4) You must identify all employees whose exposures equal or exceed the Noise Evaluation Criteria in Table 1:

You must compute employee's full-day noise exposure by using the appropriate equations from Table 2 "Noise Dose Computation" when using a sound level meter to estimate noise dose.

To conduct audiometric testing of employees exposed to noise to make sure that their hearing protection is effective.

You must provide audiograms, including any required travel or necessary additional examinations or testing, at no cost to exposed employees.

(1) You must conduct a baseline audiogram when an employee is first assigned to work involving noise exposures that equal or exceed 85 dBA TWA8.

(a) Make sure this audiogram is completed no more than one hundred eighty days after the employee is first assigned; or

(b) Make sure employee is covered by a hearing protection audit program (as described by WAC 296-817-500 and available as an alternative only for employees hired for less than one year).

(2) You must make sure employees are not exposed to workplace noise at least fourteen hours before testing to establish a baseline audiogram.

Hearing protectors may be used to accomplish this.

(3) You must notify employees of the need to avoid high levels of nonoccupational noise exposure (such as loud music, headphones, guns, power tools, motorcycles, etc.) during the fourteen-hour period immediately preceding the baseline audiometric examination.

(1) You must conduct annual audiograms for employees as long as they continue to be exposed to noise that equals or exceeds 85 dBA TWA8.

(2) You must make sure each employee is informed of the results of his or her audiometric test.

Include whether or not there has been a hearing level decrease or improvement since their previous test.

(3) You must make sure each employee's annual audiogram is compared to his or her baseline audiogram by an audiologist, otolaryngologist, another qualified physician, or the technician conducting the test to determine if a standard threshold shift has occurred.

If the annual audiogram indicates that an employee has suffered a standard threshold shift, you may obtain a retest within thirty days and consider the results of the retest as the annual audiogram.

(4) You must make sure that an audiologist, otolaryngologist, or other qualified physician sees any annual audiogram that indicates a standard threshold shift.

(1) You must make sure the health care professional supervising audiograms has:

(a) A copy of this chapter;

(b) The baseline audiogram and most recent audiogram of the employee to be evaluated;

(c) Background noise level records for the testing room;

(d) Calibration records for the audiometer.

(2) You must obtain an opinion from the health care professional supervising audiograms as to whether the audiograms indicate possible occupational hearing loss and any recommendations for changes in hearing protection.

(3) You must pay for any clinical audiological evaluation or otological examination required by the reviewer, if:

(a) Additional review is necessary to evaluate the cause of hearing loss; or

(b) If there is indication of a medical condition of the ear caused or aggravated by the wearing of hearing protectors.

(4) You must inform the employee in writing of the existence of a standard threshold shift within twenty-one calendar days of the determination.

(5) You must make arrangements for the reviewer to communicate to the employee any suspected medical conditions that are found unrelated to your workplace. This information is confidential and must be handled appropriately.

You must keep the baseline audiogram without revision, unless a qualified reviewer determines:

(1) The standard threshold shift revealed by the audiogram is persistent; or

(2) The hearing threshold shown in the annual audiogram indicates significant improvement over the baseline audiogram.

You must retain a legible copy of all employee audiograms conducted under this chapter.

Make sure the record includes:

(1) Name and job classification of the employee;

(2) Date of the audiogram;

(3) The examiner's name;

(4) Date of the last acoustic or exhaustive calibration of the audiometer;

(5) Employee's most recent noise exposure assessment;

(6) The background sound pressure levels in audiometric test rooms.

(1) You must use pure tone, air conduction, hearing threshold examinations, with test frequencies including as a minimum 500, 1000, 2000, 3000, 4000, and 6000 Hz.

(a) Tests at each frequency must be taken separately for each ear;

(b) Supra-aural headphones must be used.

(2) You must conduct audiometric tests with audiometers (including microprocessor audiometers) that meet the specifications of, and are maintained and used according to, American National Standard Specification for Audiometers, S3.6-1996.

(3) You must check the functional operation of the audiometer each day before use by doing all of the following:

(a) Make sure the audiometer's output is free from distorted or unwanted sound;

(b) Test either a person with known, stable hearing thresholds or a bio-acoustic simulator;

(c) Perform acoustic calibration for deviations of 10 dB or greater.

(4) You must check audiometer calibration must be checked acoustically at least annually to verify continued conformance with ANSI S3.6-1996. Test frequencies below 500 Hz and above 6000 Hz may be omitted from this check.

(5) You must perform an exhaustive calibration must be performed at least every two years according to the American National Standard Specification for Audiometers, S3.6-1996. Test frequencies below 500 Hz and above 6000 Hz may be omitted from the calibration.

(6) You must provide audiometric test rooms that meet the requirements of ANSI S3.1-1999 American National Standard Maximum Permissible Ambient Noise Levels for Audiometric Test Rooms using the following table of maximum ambient sound pressure levels:

This section provides options to baseline audiometric testing for employees assigned to duties with noise exposures for less than one year. These program options may also be used to provide added assessment of longer-term employees in addition to audiometric testing.

The requirements of this section apply only if you decide to use auditing or a third-party hearing loss prevention program and do not conduct baseline audiometric testing for those employees.

1. Hearing protection audits are a tool for use in evaluating your hearing loss prevention program in cases where audiometric testing does not provide a useful measure. For example, if most of your employees are hired on a temporary basis for a few months at a time, audiometric testing may not identify the small changes in hearing acuity that could occur. Auditing provides an alternative to audiometric testing in these cases.

2. Auditing is not required unless you use it in place of baseline audiometric testing for employees hired for a period of less than one year and is permitted as a substitute for audiometric testing only for these employees.

3. Third-party hearing loss prevention programs are full hearing loss prevention programs and are distinct from audiometric testing provided by third parties as part of your own hearing loss prevention program. These programs may be organized by labor groups, trade associations, labor-management cooperatives, or other organizations to:

(a) Cover a specific group of employees; or

(b) Combine efforts for several employers with common employees.

4. Although you remain responsible for the program, third-party programs can have at least two benefits over running your own program:

(a) The audiometric testing is portable between the participating employers so new testing will not be needed when an employee changes employers;

(b) Employees who only work for short periods for any one employer can be monitored under the group program over a longer period of time increasing the effectiveness of the audiometric testing in preventing hearing loss for these employees.

(1) You must conduct audits at least quarterly to provide a representative assessment of your workplace.

(a) The assessment is representative if it:

(i) Covers all processes and work activities in your business at full production levels; and

(ii) Covers all employees present on the audit day.

(b) If your business is mobile or involves variable processes, auditing may need to be repeated more often than quarterly.

(c) Auditing does not need to be repeated more than monthly as long as a reasonable effort is made to cover:

(i) The activities with greatest exposure; and

(ii) As many employees as possible.

(2) You must assess exposures and hearing protection for the full shift for each employee covered at the time of the audit.

You must make sure staff conducting hearing protection audits:

(1) Can demonstrate competence in:

(a) Evaluating hearing protection attenuation;

(b) Evaluating hearing protector choices;

(c) Assessing the correct use of hearing protectors.

(2) Are certified by the Council for Accreditation in Occupational Hearing Conservation (CAOHC) or have training in the following areas:

(a) Noise and hearing loss prevention;

(b) Washington state noise regulations;

(c) Hearing protectors;

(d) Fitting of hearing protectors;

(e) Basic noise measurement;

(f) Hearing loss prevention recordkeeping.

You must confirm that:

(1) Current site conditions during audits are consistent with conditions existing during noise monitoring.

(2) The hearing protection used by the employee is sufficient and appropriate for the conditions.

(3) The hearing protection is worn properly.

(4) The employees are satisfied with the performance and comfort of the hearing protection.

(1) You must keep a record of audit results for each employee assessed for the length of their employment and for the length of time you will rely upon the audit results.

(2) You must include the following information in the record:

(a) The make and model of the hearing protectors;

(b) The size of the protectors;

(c) Average noise exposure of the employee;

(d) Any problems found with use of the hearing protection;

(e) Any comments or complaints from the employee regarding the hearing protection.

Third-party hearing loss prevention programs are intended:

(1) For short-term employees hired or assigned to duties having noise exposures for less than one year; and

(2) For seasonal employees.

However, other employees may be included as long as you meet all requirements for hearing loss follow-ups and recordkeeping.

(1) You must make sure that the third-party program is:

(a) Equivalent to an employer program as required by this chapter; and

(b) Uses audiometric testing to evaluate hearing loss.

(2) You must make sure a licensed or certified audiologist, otolaryngologist, or other qualified physician administers the third-party program.

(3) You must make sure the third-party program has written procedures for:

(a) Communicating with participating employers of program requirements;

(b) Follow-up procedures for detected hearing loss;

(c) Annual review of participating employer programs.

(4) You must make sure the following program elements are corrected by you or the third-party program when deficiencies are found:

(a) Noise exposures;

(b) Hearing protection;

(c) Employee training;

(d) Noise controls.

(5) You must obtain a review of your hearing loss prevention program at least once per year, conducted by the third-party program administrator or their representative, in order to:

(a) Identify any tasks needing a revised selection of hearing protection; and

(b) Provide an overall assessment of the employers' hearing loss prevention activities.