Environmental Health and Safety

Hearing Protection Program

The primary objective of the Cal Poly Pomona Hearing Conservation Program (HCP) is to prevent hearing loss due to occupational noise exposure. Although Cal Poly Pomona attempts to control noise exposures on campus, certain areas and operations may expose faculty, staff, or students to significant noise levels. Per Cal/OSHA regulations (CCR, Title 8, Section 5097), all personnel who are exposed to occupational noise levels equal to or exceeding an 8-hour time-weighted average of 85 dBA shall be included in a hearing conservation program.

Hearing Conservation Program Policy

1.0 Reference
2.0 Policy
3.0 Purpose
4.0 Responsibilities
5.0 Sound Levels
6.0 Effects of Overexposure
7.0 Noise Survey
8.0 Controlling Noise
    8.1   Administrative Controls
    8.2   Engineering Controls
    8.3   Personal Protective Equipment
9.0 Control of Noise Exposure
    9.1.  Hearing Conservation Program
    9.2   Hearing Protectors
    9.3   Training Program
    9.4   Recordkeeping

 A. Safety Program Certification
    B. Common Equivalents of Sound Levels in Decibels (dB)
    C. How the Ear Hears
    D. Title 8, California Code of Regulations, Section 5095-5100
       Article 105 (Control of Noise Exposure)

California Code of Regulations, Title 8, Article 105, Sections 5095 to 5100; Business Affairs Administrative Manual, Sections 112 and 120.

It is the policy of California State Polytechnic University, Pomona to establish and maintain an effective Hearing Conservation Program (HCP) designed to eliminate or control, overexposure to harmful noise levels and to prevent occupational noise induced hearing loss to faculty, staff, and students. The University shall provide a place of employment that is safe and healthful and will not subject the campus community to avoidable hazards associated with harmful noise levels.

The University shall make every effort to identify high noise level areas on campus and shall take steps to make them readily identifiable to personnel who work in these areas. Protective measures shall be provided by means of engineering controls, administrative controls, and or by providing personal protective equipment when necessary. Employees who's 8-hour time-weighted average noise level exposure equals or exceeds 85 decibels will be enrolled in a hearing conservation program (see Section 9.1).

The University shall provide at no cost to employees a hearing examination designed to provide safe job placement of employees, satisfactory maintenance of employee hearing levels, and to ascertain the effectiveness of noise control methods.

3.1 The purpose of this program is to provide workers, supervisors, and management with an understanding of the seriousness of the threat posed by industrial noise and to explain what departments must do, by law, to control occupational noise exposure.

3.2 According to the U. S. Public Health Services, some 28 million people have their hearing impaired. An estimated 10 million cases of hearing loss are associated with (caused by) excessive noise. People who are exposed to high noise levels for long periods of time can develop noise-induced hearing loss. This is a permanently untreatable condition. Hearing aids only help to amplify different sounds, but they cannot make a person hear any better.

4.1 Environmental Health and Safety (EH&S) Office

a. coordinates the campus Hearing Conservation Program, providing consultation to departments according to their specific needs;

b. conducts noise surveys in response to department requests or upon EH&S initiative;

c. provides hearing conservation training to employees enrolled in the hearing conservation program;

d. assists departments in developing methods for noise abatement, reduction or control;

e. approves personal protective devices considered for purchase by departments;

f. establishes and conducts an audiometric testing program for appropriate employees, providing consultation and notification of exam results;

g. maintains and makes available records of exposure measurements and audiometric tests;

h. maintains records of general training activities; and

i. provides University departments with updated and current regulatory information with regard to hearing conservation.

4.2 Departments

a. ensure that noise control is considered when procuring equipment, machinery and tools;

b. identify areas that may overexpose employees to harmful levels of noise and notify the EH&S Office;

c. plan for implementation methods for noise abatement, reduction or control;

d. provide and arrange for hearing conservation training for employees covered by the Hearing Conservation Program; ensure that they read, and understand, and comply with all appropriate safety procedures, whether written or oral, and sign the Safety Program Certification Statement, Form EH&S F-333-02 (see Appendix A);

e. ensure that appropriate personal protective equipment is procured and provided to appropriate employees; enforce the use of such devices when required by Sections 8.3 and 9.2; ensure that such devices are kept in good repair and maintained in a sanitary manner; and

f. make available, to all employees, information regarding occupational hearing conservation and other relative health and safety data.

4.3 Employees

a. report any suspected high noise areas to your supervisor;

b. use common sense and good judgment at all times; the number of potential hazards that may exist or be created in the work place is sometimes unpredictable;

c. request and expect to receive (within a reasonable time frame) information regarding health and safety.

d. read, understand and comply with ail appropriate safety procedures, whether writ ten or oral, while performing assigned duties; and

e. complete and sign the Safety Program Certification Statement, Form EH&S F-333-02 (see Appendix A).

The table in Appendix B shows some common equivalents of sound levels in decibels (dB). Decibels are a unit of measure for sound. Exposure to noise with a loudness of 80dB is annoying. It is roughly equivalent to the noise level of an alarm clock about two feet from your ear. Exposure to 90dB can cause physical damage to the ear. Noise at about 120dBA, can actually be painful and permanently damaging.

6.1 The ear has three sections (see Appendix C). The outer ear helps to direct sound into the auditory canal (Ear Canal). The middle ear, separated from the outer ear by the eardrum, consists of three connected bones which transmit the vibrations of the eardrum to the inner ear. In the inner ear a snail shaped organ, the cochlea, transforms the vibrations into nerve impulses for transmission to the brain along the auditory nerve. The cochlea is lined with cells equipped with tiny hairs and is filed with liquid. As the liquid moves in response to the vibrations of the bones of the middle ear, the hairs move sending nerve impulses to the brain for decoding. The effect of continued overexposure to noise is the destruction of the hair cells and a permanent loss of hearing.

6.2 The first warning of hearing loss is often the inability to hear high frequency sounds. People with hearing deficiencies caused by overexposure to noise lose sensitivity to sound at about 4,000 Hz, the approximate frequency of a voice on the telephone. If the overexposure continues, the damage will gradually be extended until the entire hearing range is affected. As more and more hair cells of the inner ear are destroyed, the ability to hear is progressively and permanently reduced. Damaged hair cells cannot be repaired or replaced. As a person loses sensitivity to higher frequencies, sounds become distorted. He/she may be able to hear a conversation but not be able to understand it. The use of a hearing aid makes the sound louder, but not clearer. The sound will still be distorted.

6.3 Overexposure to noise affects the entire body. It is associated with tinnitus (ringing in the ears), increased pulse rate, hypertension, increased secretion of certain hormones, tiredness, nervousness, sleeplessness, and other symptoms of stress.

6.4 How can you tell there is a noise problem where you work? Common indications of overexposures to noise are:

a. difficulty hearing normal speech in the work area.

b. raised voice level for communication at normal distance.

c. ringing in the ears after leaving the work area.

6.5 If you suspect that there is a noise problem, the next step is to request a noise survey. The purpose of the survey is to:

a. measure the noise levels for an area or work task

b. identify the source of the noise, and

c. determine what corrective measures to take

Noise surveys are technically complicated and require expensive equipment. The EH&S Office has the necessary equipment to conduct noise level surveys. If a noise survey is needed, the affected employee may inform his/her supervisor who will in turn request this service from the EH&S Office. Noise surveys fall into two broad categories. They are:

a. Preliminary noise survey

b. Detailed noise survey

7.1 The preliminary noise survey, for all practical matters is not a real survey, rather it is an assessment of the noise types and levels in a given area. This survey is useful in determining if a potential noise problem exists.

7.2 The detailed noise survey involves the collection of specific data during three main steps:

a. Area measurements

b. Workstation measurements

c. Exposure duration

7.3 There are four reasons for the detailed survey.

a. To obtain specific information from a work station.

b. Develop guidelines for establishing controls.

c. Define areas where hearing protection is required, and

d. Determine the need for employee inclusion into a hearing conservation program.

The most effective controls are engineering controls introduced at the time a structure or machinery is being designed or installed. When the facilities have been built and machinery is already in place and operating, such controls are likely to be more expensive.

If the noise survey reveals a potentially high noise problem there are usually many alternative ways to reduce the exposure to within acceptable limits. The EH&S Office should be able to help the department choose a method which is not only effective but which is also economically feasible.

8.1 Administrative Controls. These may also be referred to as operational controls. Administrative controls include adjusting work schedules to reduce exposure time; limiting machine- operating time; or restricting equipment purchases to a specified maximum sound level.

8.2 Engineering Controls. Engineering controls include barriers, damping, isolation; musing, noise absorption, mechanical isolation, variations in force, pressure or driving speed, and combinations of these and other means of reducing noise. Engineering controls, which regulate noise at its source, often involves customized equipment modifications. Cost for these controls can be expensive, however. Depending on the situation, a combination of Administrative and Engineering controls can be effective and affordable.

8.3 Personal Protective Equipment. When engineering and/or administrative controls either fail to reduce to within acceptable limits or are not technologically feasible, hearing protectors must be used.

When either ear muffs or ear plugs are used, the department should have a sufficient variety to insure that workers can get a good fit. Protective devices should be both effective and comfortable. Ear plugs are made of soft, flexible materials which will conform to the shape of the wearer's ear canal.

When ear muffs are used, make sure that the seal between the muff and the head is tight. Long hair, glasses, and other obstructions may diminish the effectiveness of the device.

The State of California has adopted a set of regulations governing exposure of workers to noise in the workplace. The regulations set exposure limits and detail the University's responsibilities when the limits are exceeded.

The following is a summary of the General Industry Safety Orders regulating exposure of workers to occupational noise. The actual regulations are attached for reference (see Appendix D).

9.1 Hearing Conservation Program. When workers are exposed to an 8-hour time-weighted average (TWA) of 85 decibels or greater, the University shall institute a hearing conservation program which includes monitoring exposure, audiometric testing and evaluation of the audiogram results for all exposed workers.

Required audiometric testing must be conducted by a licensed audiologist, otolaryngologist, qualified physician, or trained technician, and the tests made available to employees. Annual audiograms are compared with the baseline audiogram to determine if there has been any deterioration of the worker's hearing (threshold shift). if a worker suffers a significant threshold shift, the University must fit or refit the worker with hearing protectors, train or retrain him/her in their use, and make sure they are used.

9.2 Hearing Protectors. OSHA's Hearing Conservation Amendments specifies that Hearing Protectors (HP) must be made available to employees when their TWA daily noise exposures exceed 85 dBA and mandates the use of HP when exposures exceed 90dBA. Workers must wear hearing protectors when:

they are exposed to a sound level of 85 dBA or greater and have had a significant threshold shift in hearing.

they are exposed to noise in excess of the limits set in Table N-1 Permissible Noise Exposure, Section 5096 of the California Code of Regulations under Title 8. (Appendix D).

Departments have the responsibility to offer workers a variety of suitable hearing protectors, train workers in the use and care of the devices, and ensure the proper initial fit.

9.3 Training Program. Departments that employ workers who are exposed to noise at or above 85 dBA shall include those employees in an annual training program and shall ensure employee participation in such program. The program topics will include:

a. the effects of noise on hearing,

b. the purpose and effectiveness of hearing protectors, and

c. the purpose and an explanation of audiometric testing.

The department must make available to workers the Cal-OSHA regulations on exposure to noise (see Appendix D or Article 105 of the Cal-OSHA Safety Orders).

9.4 Recordkeeping and Records Access. EH&S Office will maintain records of:

a. exposure measurements for at least 2 years,

b. audiometric tests for the duration of the affected employee's employment, and

c. audiometric test rooms for the same period.

These records must be made available to workers, former workers, worker representatives, and authorized representatives of the Division of Occupational Safety and Health The Request for Medical and Exposure Records Access, Form EH&S F-251 -00, and Authorization for Release of Medical Record Information, Form EH&S F-1665-00, shall be used for this purpose.



I certify that I have read the foregoing safety program and fully
understand my responsibilities with respect to the policy and
procedures as outlined. l further agree to comply with the
provisions of this program.


EMPLOYEE SIGNATURE                                                            DATE


Distribution:    Department Office - White
		Employee- Canary
		Personnel Services - Pink

EH&S F-333-02 Fee 3/95



Jet Plane
Gunshot                            140

Riveting (steel tank)              130

Auto Horn
Thunder                            120

Power Saw
Rock Band                          110

Punch Press
Garbage Truck                      100

Heavy Truck                         90

Alarm Clock                         80

Conversation                        70

Soft Whisper                        30


Exposure to noise with a loudness of 80dB is annoying. It is roughly equivalent to the noise level of an alarm clock about two feet from your ear. Exposure to a 90 dBA (A = time weighted average) can cause physical damage to the ear. At about 120 dBA hearing actually becomes painful and damage to hearing, certain and rapid.

Diagram of the ear, showing outer ear, middle ear, and inner ear

Acoustic Calibration of Audiometers

I. Audiometer calibration shall be checked acoustically, at least annually, according to the procedures described in this Appendix. The equipment necessary to perform these measurements is a sound level meter, octave-band filter set, and a National Bureau of Standards 9A coupler. In making these measurements, the accuracy of the calibrating equipment shall be sufficient to determine that the audiometer is within the tolerances permitted by ANSI S3.6-1969.

(a) Sound Pressure Output Check.

(1) Place the earphone coupler over the microphone of the sound level meter and place the earphone on the coupler.

(2) Set the audiometer's hearing threshold level (HTL) dial to 70 dB.

(3) Measure the sound pressure level of the tones at each test frequency from 500 Hz through 6000 Hz for each earphone.

(4) At each frequency the readout on the sound level meter should correspond to the levels in Table D-1 or Table D-2, as appropriate, for the type of earphone, in the column entitled "sound level meter reading."

(b) Linearity Check.

(1) With the earphone in place, set the frequency to 1000 Hz and the HTL dial on the audiometer to 70 dB.

(2) Measure the sound levels in the coupler at each 10dB decrement from 70 dB to 10 dB, noting the sound level meter reading at each setting.

(3) For each 10-dB decrement on the audiometer, the sound level meter should indicate a corresponding 10 dB decrease.

(4) This measurement may be made electrically with a voltmeter connected to the earphone terminals.

(c) Tolerances.

When any of the measured sound levels deviate from the levels in Table D-1 or Table D-2 by 3 dB at any test frequency between 500 and 3000 Hz, 4 dB at 4000 Hz, or 5 dB at 6000 Hz, an exhaustive calibration is advised. An exhaustive calibration is required if the deviations are 15 dB or greater at any test frequency.

Table D-2

		Reference Threshold Levels for Telephonics TDH-39 Earphones
				Reference Threshold
				Level for TDH-39
Frequency			Hz Earphones dB		Sound Level Meter Reading, dB
500				11.5			81.5
1000				7			77
2000				9			79
3000				10			80
4000				9.5			79.5
6000				15.5			85.5

Table D-2

		Reference Threshold Levels for Telephonics TDH-49 Earphones
				Reference Threshold
				Level for TDH-49
Frequency			Hz Earphones dB		Sound Level Meter Reading, dB

500				13.5			83.5
1000				7.5			77.5
2000				11			81.0
3000				9.5			79.5
4000				10.5			80.5
6000				13.5			83.5

Note: Authority and reference cited: Section 142.3, Labor Code.

Methods for Estimating the Adequacy of Hearing Protector


I. For employees who have experienced a standard threshold shift, hearing protector attenuation must be sufficient to reduce employee exposure to a TWA of 85 dB. Employers must select one of the following methods by which to estimate the adequacy of hearing protection attenuation.

II. The most convenient method is the Noise Reduction Rating (NRR) developed by the Environmental Protection Agency (EPA). According to EPA regulation, the NRR must be shown on the hearing protector package. The NRR is then related to an individual worker's noise environment in order to assess the adequacy of the attenuation of a given hearing protector. This Appendix describes four methods of using the NRR to determine whether a particular hearing protector provides adequate protection within a given exposure environment. Selection among the four procedures is dependent upon the employer's noise measuring instruments.

III. Instead of using the NRR, employers may evaluate the adequacy of hearing protector attenuation by using one of the three methods developed by the National Institute for Occupational Safety and Health (NIOSH), which are described in the "List of Personal Hearing Protectors and Attenuation Data," HEW Publication No. 76-120, 1975, pages 21-37. These methods are known as NIOSH methods #1, #2 and #3. The NRR described below is a simplification of NIOSH method #2. The most complex method is NIOSH method #1, which is probably the most accurate method since it uses the largest amount of spectral information from the individual employee's noise environment. As in the case of the NRR method described below, if one of the NIOSH methods is used, the selected method must be applied to an individual's noise environment to assess the adequacy of the attenuation. Employers should be careful to take a sufficient number of measurements in order to achieve a representative sample for each time segment. Note: The employer must remember that calculated attenuation values reflect realistic values only to the extent that the protectors are properly fitted and worn.

IV. When using the NRR to assess hearing protector adequacy, one of the following methods must be used:

(a) When using a dosimeter that is capable of C-weighted measurements:

(1) Obtain the employee's C-weighted dose for the entire workshift, and convert to TWA (see Appendix A).

(2) Subtract the NRR from the C-weighted TWA to obtain the estimated A-weighted TWA under the ear protector.

(b) When using a dosimeter that is not capable of C-weighted measurements, the following method may be used:

(1) Convert the A-weighted dose to TWA (see Appendix A).

(2) Subtract 7 dB from the NRR.

(3) Subtract the remainder from the A-weighted TWA to obtain the estimated A-weighted TWA under the ear protector.

(c) When using a sound level meter set to the A-weighting network:

(1) Obtain the employee's A-weighted TWA.

(2) 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.

(d) When using a sound level meter set on the C-weighting network:

(1) Obtain a representative sample of the C-weighted sound levels in the employee's environment.

(2) Subtract the NRR from the C-weighted average sound level to obtain the estimated A-weighted TWA under the ear protector.

Note: Authority and reference cited: Section 142.3, Labor Code.


1. Amendment filed 10-3-83; effective thirtieth day thereafter (Register 83, No. 41).

Determination and Application of Age Corrections to Audiograms

As permitted by Section 5097(d)(9), increases in an employee's hearing thresholds, as evidenced by an audiogram taken subsequent to a baseline audiogram, may be adjusted (lowered) for presbycusis (hearing loss due to aging). The applicable correction values at various ages and sound frequencies are included in Table F. If the employer chooses to adjust an employee's audiogram pursuant to Section 5097(d)(9), the employer shall follow the procedure described below.

(a) Obtain from Table F the age correction values at each audiometric test frequency of interest (the hearing losses at 2000, 3000, and 4000Hz are relevant to the determination of whether a standard threshold shift, as defined by Section 5097(d)(8), may exist) for the employee by:

(1) Finding the age at which the most recent audiogram was taken and recording the corresponding age correction values; and

(2) Finding the age at which the baseline audiogram was taken and recording the corresponding age correction values.

(b) Subtract the values found in (a)(2) from those found in (a)(1). (The remainders from these subtractions represent the values (in decibels) which may be attributed to aging and are the values by which the most recent audiogram may be adjusted at the respective audiometric test frequencies.)

(c) Subtract the values found in (b) from the hearing threshold values of the most recent audiogram.

When the adjustment of an audiogram for hearing loss due to aging is performed for the purpose of determining whether a standard threshold shift has occurred, the above-described calculations may be restricted to the 2000, 3000, and 4000 Hz frequencies. If the average of the hearing threshold values at 2000, 3000, and 4000 Hz found in step (c), above, is equal to or greater than 10, then the employee has exhibited a standard threshold shift, and the employer must comply with various provisions of Section 5097(d) as well as certain other requirements such as Sections 5098(a)(2)(B)2 and (b)(3).

Table F.  Age Correction Values in Decibels for Males (M) and Females (F)

				Audiometric Test Frequencies (Hz)
Age		1000		2000		3000		4000		6000
		M	F	M	F	M	F	M	F	M	F
20 or Younger	5	7	3	4	4	3	5	3	8	6
21		5	7	3	4	4	4	5	3	8	6
22		5	7	3	4	4	4	5	4	8	6
23		5	7	3	5	4	4	6	4	9	7
24		5	7	3	5	5	4	6	4	9	7
25		5	8	3	5	5	4	7	4	10	7
26		5	8	4	5	5	5	7	4	10	8
27		5	8	4	5	6	5	7	5	11	8
28		6	8	4	5	6	5	8	5	11	8
29		6	8	4	5	6	5	8	5	12	9
30		6	8	4	6	6	5	9	5	12	9
31		6	8	4	6	7	6	9	5	13	9
32		6	9	5	6	7	6	10	6	14	10
33		6	9	5	6	7	6	10	6	14	10
34		6	9	5	6	8	6	11	6	15	10
35		7	9	5	6	8	7	11	7	15	11
36		7	9	5	7	9	7	12	7	16	11
37		7	9	6	7	9	7	12	7	17	12
38		7	10	6	7	9	7	13	7	17	12
39		7	10	6	7	10	8	14	8	18	12
40		7	10	6	7	10	8	14	8	19	13
41		7	10	6	8	10	8	14	8	20	13
42		8	10	7	8	11	9	16	9	20	13
43		8	11	7	8	12	9	16	9	21	14
44		8	11	7	8	12	9	17	9	22	14
45		8	11	7	8	13	10	18	10	23	15
46		8	11	8	9	13	10	19	10	24	15
47		8	11	8	9	14	10	19	11	24	16
48		9	12	8	9	14	11	20	11	25	16
49		9	12	9	9	15	11	21	11	26	16
50		9	12	9	10	16	11	22	12	27	17
51		9	12	9	10	16	12	23	12	28	17
52		9	12	10	10	17	12	24	13	29	18
53		9	13	10	10	18	13	25	13	30	18
54		10	13	10	11	18	13	26	14	31	19
55		10	13	11	11	19	14	27	14	32	19
56		10	13	11	11	20	14	28	15	34	20
57		10	13	11	11	21	15	29	15	35	20
58		10	14	12	12	22	15	31	16	36	21
59		11	14	12	12	22	16	32	16	37	21
60 or Older	11	14	13	12	23	16	33	17	38	22

Note: Authority and reference cited: Section 142.3, Labor Code.


1. New Appendix F filed 10-3-83; effective thirtieth day thereafter (Register 83, No. 41).