(7-1-97)

04. Equivalent Sound Level Contours: (7-1-97)

a. When noise levels are determined by octave band analysis, the equivalent A-weighted sound level may be determined by using the graph in figure 160.04-A. (7-1-97)

FIGURE 160.04-A BAND CENTER FREQUENCY IN CYCLES PER SECOND

b. Octave band sound pressure levels may be converted to the equivalent A-weighted sound level by plotting them on the graph in Figure 160.04-A and noting the A-weighted sound level corresponding to the point of highest penetration into the sound level contours. This equivalent A-weighted sound level, which may differ from the actual A-weighted sound level of the noise, is used to determine exposure limits from Table 160.03-A. (7-1-97)

05. Engineering Controls: (7-1-97)

a. When employees are subjected to sound exceeding those listed in Table 160.03-A, feasible administrative or engineering controls shall be utilized. If such controls fail to reduce sound levels within the levels of Table 160.03-A, proper protective equipment shall be provided and used to reduce sound levels within the levels of the Table. (7-1-97)

06. Variations in Level: (7-1-97)

a. If the variations in noise level involve maxima at intervals of one (1) second or less, it is to be considered continuous. (7-1-97)

07. Hearing Conservation Program: (7-1-97)

a. In all cases where the sound levels equal or exceed an eight (8) hour time weighted average sound level (TWA) of eighty-five (85) decibels measured on the A scale (slow response)or, equivalently, a dose of fifty (50) percent, a continuing effective hearing conservation program shall be administered. (7-1-97)

b. For the purposes of the hearing conservation program, employee noise exposures shall be computed in accordance with sub-section 160.12 and table 160.12-A, and without regard to any attenuation provided by the use of personal protective equipment. (7-1-97)

c. For the purposes of this section, an eight (8) hour time weighted average of eighty-five (85) decibels or a dose of fifty (50) percent shall also be referred to as the action level. (7-1-97)

d. When information indicates that any employee's exposure may equal or exceed an eight (8) hour time weighted average of eighty-five (85) decibels, the employer shall develop and implement a monitoring program. The sampling strategy shall be designed to identify employees for inclusion in the hearing conservation program and to enable proper selection of hearing protectors. Where circumstances such as high 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 sub-section unless the employer can show that area sampling produces equivalent results. All continuous, intermittent, and impulsive sound levels from eighty (80) decibels to one-hundred-thirty (130) decibels shall be integrated into the noise measurements. Monitoring shall be repeated whenever a change in production, process, equipment, or controls increase noise exposures to the extent that: additional employees may be exposed at or above the action level; or the attenuation provided by hearing protectors being used by employees may be rendered inadequate to meet the requirements of sub-section 160.10.g of this section. (7-1-97)

e. The employer shall notify each employee exposed at or above an eight (8) hour time weighted average of eighty-five (85) decibels of the result of the monitoring. (7-1-97)

f. The employer shall provide affected employees or their representatives with an opportunity to observe any noise measurements conducted pursuant to this section. (7-1-97)

g. Exposure to impulsive or impact noise shall not exceed one-hundred-forty (140) db peak sound pressure level. (7-1-97)

08. Audiometric Testing Program: (7-1-97)

a. The employer shall establish and maintain an audiometric testing program as provided in this paragraph by making audiometric testing available to all employees whose exposure equal or exceed an eight (8) hour time weighted average of eighty-five (85) decibels. (7-1-97)

b. The program shall be provided at no cost to employees. (7-1-97)

c. Audiometric tests shall be performed by a licensed or certified audiologist, otolaryngologist, or physician. (7-1-97)

d. All audiograms obtained pursuant to this section shall meet the requirements of sub-section 160.09 of this section. (7-1-97)

e. Within six (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. Where mobile test vans are used to meet the audiometric testing obligation, the employer shall obtain a valid baseline audiogram within one (1) year of an employee's first exposure at or above the action level. Where baseline audiograms are obtained more than six (6) months after the employee's first exposure at or above the action level, employees shall wear hearing protectors for any period exceeding six (6) months after the first exposure until the baseline audiogram is obtained. (7-1-97)

f. Testing to establish a baseline audiogram shall be preceded by at least fourteen (14) hours without exposure to work place noise. Hearing protectors may be used as a substitute for the requirement that baseline audiograms be preceded by fourteen (14) hours without exposure to workplace noise. The employer shall notify employees of the need to avoid high levels of non-occupational noise exposure during the fourteen (14) hour period immediately preceding the audiometric examination. (7-1-97)

g. At least annually after obtaining the baseline audiogram, the employer shall obtain a new audiogram for each employee exposed at or above an eight (8) hour time weighted average of eighty (85) decibels. (7-1-97)

h. Each employees annual audiogram shall be compared to that employee's baseline audiogram to determine if the audiogram is valid and if a standard threshold shift has occurred. This comparison may be done by a trained technician. If the annual audiogram shows that an employee has suffered a standard threshold shift, the employer may obtain a retest within thirty (30) days and consider the results of the retest as the annual audiogram. The audiologist, otolaryologist, or physician shall review problem audiograms and shall determine whether there is a need for further evaluation. The employer shall provide to the person performing this evaluation the following information: (7-1-97)

i. A copy of the requirements for hearing conservation as set forth in this section; (7-1-97)

ii. The baseline audiogram of the employee to be evaluated; (7-1-97)

iii. Measurements of background sound pressure levels in the audiometric test room as required by this section for audiometric test rooms; (7-1-97)

iv. And records of audiometer calibrations as required by this section. (7-1-97)

i. If a comparison of the annual audiogram to the baseline audiogram indicated a standard threshold shift as defined herein has occurred, the employee shall be informed of this fact in writing, within twenty-one (21) days of the determination. 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: employees not using hearing protectors shall be fitted with hearing protectors, trained in their use and care, and required to use them; 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; and the employee shall be informed of the need for an otological examination if a medical pathology of the ear that is unrelated to the use of hearing protectors is suspected. (7-1-97)

j. If subsequent audiometric testing of an employee whose exposure to noise is less than an eight (8) hour time weighted average of nighty (90) decibels indicates that a standard threshold shift is not present, the employer: shall inform the employee of the new audiometric interpretation; and may discontinue the required use of hearing protectors for that employee. (7-1-97)

k. An annual audiogram may be substituted for the baseline audiogram when, in the judgement of the audiologist, otolaryngologist, or physician who is evaluating the audiogram: the standard threshold shift revealed by the audiogram is persistent; the hearing threshold shown in the annual audiogram indicates significant improvement over the baseline audiogram. (7-1-97)

l. As used in this section, a standard threshold shift is a change in the hearing threshold relative to the baseline audiogram of an average of ten (10) dB or more at two-thousand (2000), three-thousand (3000), and four-thousand (4000) Hz in either ear. (7-1-97)

m. In determining whether a standard threshold shift has occurred, allowance may be made for the contribution of aging (presbycusis) to the change in hearing level by correcting the annual audiogram. (7-1-97)

09. Audiometric Test Requirements: (7-1-97)

a. Audiometric tests shall be pure tone, air conduction, hearing threshold examinations, with test frequencies including as a minimum five-hundred (500), one-thousand (1000), two-thousand (2000), three-thousand (3000), four-thousand (4000), and six-thousand (6000) Hz. Tests at each frequency shall be taken separately for each year. (7-1-97)

b. Audiometric tests shall be conducted with audiometers (including microprocessor audiometers) that meet the specifications of, and are maintained in accordance with, the American National Standard Specification for Audiometers, S3.9. (7-1-97)

c. Pulsed tone and self recording audiometers, if used, shall meet the requirements of sub-section 160.13 of this section. (7-1-97)

d. Audiometric examinations shall be administered in a room meeting the following requirements: Rooms used for audiometric testing shall not have background sound pressure levels exceeding those in table 160.09-A when measured with equipment conforming to at least to the Type-two (2) requirements of American National Standard Specification for Sound Level Meters, S1.4 and to Class II requirements of American National Standard Specification for Octave, Half-Octave, and Third-octave Band Filter Sets, S1.11. (7-1-97)