Wearing Hearing Protection Properly

Workplace

Safety and Health

Department of Health and Human Services

Centers for Disease Control and Prevention

National institute for Occupational Safety and Health

A 3-D training aid for drillers

Information Circular/2004

IC 9472
Information Circular 9472 

Wearing Hearing Protection Properly: 

A 3-D Training Aid for Drillers 

By Edward A. Barrett and Roberta A. Calhoun 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Pittsburgh Research Laboratory 

Pittsburgh, PA 

November 2004
ORDERING INFORMATION 

Copies of National Institute for Occupational Safety and Health (NIOSH) 

documents and information 

about occupational safety and health are available from 

NIOSH–Publications Dissemination 

4676 Columbia Parkway 

Cincinnati, OH 45226–1998 

 FAX 513–533–8573 

 Telephone: 1–800–35–NIOSH 

 (1–800–356–4674) 

 E-mail: pubstaft@cdc.gov 

 Web site: www.cdc.gov/niosh 

This document is the public domain and may be freely copied or reprinted. 

____________________________________ 

Disclaimer: Mention of any company or product does not constitute endorsement by NIOSH. 

DHHS (NIOSH) Publication No. 2005–107 
Table of Contents 

Introduction 1 

Acknowledgment 1 

Training aid summary 2 

How to use the training aid 3 

Performance objectives 4 

Discussion notes 5 

Summary of field test results 13 

Answer key for pretest / posttest questions 14 

Appendices 

 Appendix A: Pretest / Posttest questions 
Wearing Hearing Protection Properly 

1 

WEARING HEARING PROTECTION PROPERLY: 

A 3-D TRAINING AID FOR DRILLERS 

By Edward A. Barrett1 and Roberta A. Calhoun2

Introduction 

This Instructor’s Copy contains most of the information needed to use the Wearing 

Hearing Protection Properly 3-D training reel. It offers practical suggestions on how to 

use the reel as a training aid, performance objectives for deciding if the training is 

appropriate for your needs, and discussion notes that provide additional information to 

the user. 

The 3-D reel was designed as a self-teaching aid that drillers and others who work at a 

drill site can use wherever the opportunity for such training presents itself. The latter 

could be a company preshift requirement or a tailgate session where workers would 

have an opportunity to view and discuss the reel. It could also be an individual looking 

at the reel in a pickup truck prior to beginning work at a drill site. The 3-D training reel is 

versatile in that it can be used for a small group of persons or for a single worker. For 

any of these situations, information is transferred to the individual by viewing each of the 

seven colorful, in-depth 3-D scenes and relating the words that appear in each scene to 

what is depicted in the visual. 

Acknowledgment 

The authors thank Linda J. McWilliams, Statistician, NIOSH Pittsburgh Research 

Laboratory, for her assistance in analyzing the experimental data in this document. 

 

1

Mining engineer. 

2

Safety and occupational health specialist. 

Pittsburgh Research Laboratory, National Institute for Occupational Safety and Health, Pittsburgh, PA. 
Wearing Hearing Protection Properly 

2 

Training Aid Summary 

The following summary information is provided to help you decide if this training aid is 

appropriate for your needs. 

Type: 3-D reel containing seven (7) scenes 

Length: Approximately 15 minutes, depending on choice of group or individual 

sessions and length of followup discussions 

Skills: Inserting foam earplugs properly 

 Understanding use of both earplugs and earmuffs 

 Identifying improper use of earmuffs 

 Recognizing personal responsibility for wearing hearing protection 

Location: Surface drill site 

Situation: Seven scenes show the proper use of foam earplugs and earmuffs. Each 

scene shows workers near a large drill wearing both types of hearing 

protection. Words are embedded within each scene that provide 

important information. 

There is a related training exercise available entitled Drill Rig Incident, DHHS (NIOSH) 

Publication No. 2005–108 (IC 9473). It can be obtained by contacting NIOSH at: 

Telephone: 1–800–35–NIOSH (1–800–356–4674) 

Fax: 513–533–8573 

E-mail: pubstaft@cdc.gov 

www.cdc.gov/niosh 
Wearing Hearing Protection Properly 

3 

How to Use the Training Aid 

1. Look at the performance objectives on the next page. Decide if the training aid is 

appropriate for your needs. 

2. Look at the 3-D reel. 

3. Review the discussion notes for each scene in the reel. 

4. Decide how (either group or individual) and where (either company training facility 

or at the drill site) you want to use the training aid with your employees. 

• Have each person take the pretest found in appendix A. Be sure to read the 

directions carefully before beginning the pretest. 

• Give each person a reel and 3-D viewer. For individual training at a drill site, 

these may be left in the cab of the drill or in a pickup truck. 

• Demonstrate how to insert the reel into the viewer and how to achieve optimum 

lighting (by looking at the sky if outside, or at ceiling lights if inside). 

• Have the individual worker or group of workers look at the 3-D reel. 

• Have each person take the posttest found in appendix A. Be sure to read the 

directions carefully before beginning the posttest. 

• As appropriate, review and discuss scenes with the trainee(s). Add your own 

ideas. This can be done immediately after the training. This followup is 

important in order to reinforce the ideas presented. 
Wearing Hearing Protection Properly 

4 

Performance Objectives 

Objective Capability Description of required performance and conditions 

Number Verb(s) under which it is to occur 

1. EP3

 Recall Basic procedures for inserting foam earplugs 

 Apply properly 

 

2. EM Recall Basic information for wearing earmuffs properly 

 Apply 

3. HP Recognize Proper use of hearing protection is an 

 individual’s responsibility 

4. HP Recall Information for wearing double hearing protection 

 Apply 

 

3

Skill and knowledge domain abbreviations: 

EP = Foam earplugs 

EM = Earmuffs 

HP = Hearing protection 
Wearing Hearing Protection Properly 

5 

Discussion Notes 

General Information

NIOSH researchers have observed during drill site visits that hearing protection devices 

are often misused. As a result, workers may be exposed to excessive levels of noise 

without realizing it because they think they are wearing their hearing protection properly. 

The purpose of this training aid is to teach workers about the correct use of hearing 

protection. 

This 3-D training aid is designed to be self-teaching. The visuals are self-instructional 

because each scene contains wording that briefly and simply describes the particular 

hearing protection-related activity being shown. As such, no additional information is 

needed to explain and reinforce the message. 

The 3-D reel can be used either by an individual as informal on-the-spot training or by a 

group of workers in a company-initiated instructional effort. After viewing the 3-D reel, 

trainees generally look forward to discussing what they see; this serves to reinforce the 

lesson. Discussions may be held immediately after completing the training or within the 

next few days. Use the information presented here, along with your own ideas, for 

dialogue with individual workers or with groups of workers. This will not only help to 

strengthen knowledge and skills learned, but will also relate the subject to their personal 

experiences and thus become more meaningful for them. 

The following discussion notes provide additional information for your use. The notes 

are below a 2-D picture of each 3-D scene on the reel. (Note how much more detail can 

be seen in 3-D compared to the standard two-dimensional pictures shown here.) Read 

through the notes prior to the actual training activity. Incorporate the information you 

find here with your own knowledge and make these points, as appropriate, in your 

followup discussions. 
Wearing Hearing Protection Properly 

6 

Scene 1: Wearing hearing protection properly

The two most common types of hearing protection used in the drilling industry are foam 

earplugs and earmuffs. To achieve maximum benefit from either of these, they must be 

worn properly. 

Improper use of both earplugs and earmuffs has been observed among drillers. In 

some cases, foam earplugs were not inserted far enough; in others, they worked their 

way loose because of head and body movement during work activities. Regardless, 

earplugs are of little value if they do not fit snug and well within the person’s ear. 

The improper use of earmuffs typically results in an ineffective seal around the ear and 

reduced hearing protection. 
Wearing Hearing Protection Properly 

7 

Scene 2: Roll and squeeze foam ear plugs

Before inserting foam earplugs, they should be rolled into a very thin, crease-free

cylinder. In order to get the diameter of the cylinder as small as possible and creasefree, you should begin by squeezing the earplug lightly as you roll it between your 

forefinger and thumb. Then gradually apply progressively greater pressure as the plug 

becomes more tightly compressed. 

The earplug may also be rolled in a person’s palms to achieve the thin, crease-free

cylinder. This may be necessary for the person who has small or thin fingers, in which 

case the cylinder could end up in a distorted “barbell” shape. 

A mistake that some people make is to unintentionally roll the foam earplug into a ball or 

cone, instead of a cylinder. This results in a configuration that cannot be inserted very 

far into the ear canal and therefore will not provide effective hearing protection. 
Wearing Hearing Protection Properly 

8 

Scene 3: Pull ear up and back – insert rolled plug

In order for the rolled and squeezed cylinder to be inserted into your ear properly, you 

must reach one hand around the back of your head and pull up and back on your outer 

ear to straighten the ear canal. If the ear canal is not straightened out, the earplug 

cannot slide in far enough because of the natural curve inside your ear. You should be 

able to feel when the earplug is in far enough to provide a good seal. 
Wearing Hearing Protection Properly 

9 

Scene 4: Hold plug in ear until expanded

Foam earplugs must be held in your ear with your finger for 10–20 seconds to allow 

them to expand. Then, to ensure the best fit possible, you should release and push 

again for another 5 seconds. At this point, the earplug will be positioned entirely within 

your ear canal. 
Wearing Hearing Protection Properly 

10 

Scene 5: Both muffs and plugs for extremely loud noise

Extremely loud noise may include power saws, guns, pneumatic hammers, radio 

earphones, and jet airplanes at takeoff. 

NIOSH’s guideline for using double hearing protection (wearing both earplugs and 

earmuffs) is for noise exposures that exceed 100 dBA over an 8-hour period. In the 

mining industry, workplace noise levels of 105 dBA or more over an 8-hour period 

require mine operators to ensure the use of both earplug and earmuff hearing 

protectors. 
Wearing Hearing Protection Properly 

11 

Scene 6: Glasses and facial hair can cause a bad seal

The ability of earmuff cushions to seal around the ear is reduced if they are worn over 

heavy beards, long hair or sideburns, and the sidepieces of eyeglasses. In these 

cases, the seal is likely to be altered, which will result in loss of hearing protection. 

To help in maintaining a good seal, it is important that eyeglass sidepieces fit close to 

the worker’s head and be as thin as possible. 
Wearing Hearing Protection Properly 

12 

Scene 7: Wear hearing protection properly

Hearing loss can be prevented by protecting your hearing in every way possible. 

This includes wearing hearing protection both on and off the job. 

The responsibility for wearing hearing protection rests with each worker who may 

be exposed to loud noise at a drill site. 

Hey! It’s Up to You! 

... Choose effective hearing protectors 

... Wear hearing protectors properly 

... Care for and maintain hearing protectors 
Wearing Hearing Protection Properly 

13 

Summary of Field Test Results 

NIOSH evaluated the 3-D reel, Wearing Hearing Protection Properly, to determine if it is 

effective for teaching drillers about the proper use of foam earplugs and earmuffs. 

A simple field experiment was conducted using a sample of 76 persons. The subjects 

were voluntary participants recruited from conference workshops (National Drilling 

Association and National Ground Water Association) and drilling company training 

classes. The procedure used in the experiment was as follows: 

Participants were asked to answer eight multiple-choice questions (see appendix A) 

related to using both types of hearing protection. They were then told to take as much 

time as needed to view and understand the information shown in all seven scenes on 

the 3-D reel. Afterward, they were instructed to review their answers in the multiplechoice test and change any they believed to be incorrect. To accomplish this, two sets 

of answer choices were placed on the multiple choice test sheet—one set in blue 

(answered before the training), the other set in red (answered after the training). It was 

theorized that their decision to change answers would be directly related to what they 

learned from viewing the 3-D reel. 

The number of correct answers recorded after viewing the 3-D reel (posttest) was 

expected to be greater than the number of correct answers recorded prior to viewing the 

reel (pretest). Such an outcome would support the belief that subjects could learn about 

the proper use of hearing protection from the training aid. Therefore, it would be 

concluded that the 3-D reel is an effective training aid for drillers. 

The following data were recorded for the experiment: 

Subjects had more correct multiple choice answers after viewing the 3-D reel (7.24) 

than before (6.13). The change in scores was highly significant. It was concluded, 

therefore, that the 3-D training aid was effective for teaching drillers about wearing 

hearing protection properly. 

Paired T-test 

N=76 

Mean Standard 

deviation t-value p-value 

Pretest 6.13 0.998 — — 

Posttest 7.24 0.978 9.38 <0.001 
Wearing Hearing Protection Properly 

14 

Answer Key for Pretest / Posttest Questions 

Wearing Hearing Protection Properly

1. Which type of hearing protection is it possible to wear improperly? 

a. foam ear plugs a. foam ear plugs

b. earmuffs b. earmuffs

c. neither a nor b c. neither a nor b

 d. both a and b d. both a and b

2. Before placing foam ear plugs in your ears, you should... 

 a. roll them in your fingers a. roll them in your fingers

b. squeeze them with your fingers b. squeeze them with your fingers

 c. roll and squeeze them c. roll and squeeze them

d. none of the above d. none of the above

3. Foam ear plugs should be inserted into your ear canals by... 

a. pushing them in with your forefinger until snug 

b. pulling up and back on ears to open up the canal 

c. neither a nor b 

d. both a and b

a. pushing them in with your forefinger until snug 

b. pulling up and back on ears to open up the canal 

c. neither a nor b 

d. both a and b

4. The snug fit of foam ear plugs is achieved by... 

a. inserting them into your ear as far as possible, then letting them expand 

b. holding them in with your finger until they expand 

c. neither a nor b

d. both a and b

a. inserting them into your ear as far as possible, then letting them expand 

b. holding them in with your finger until they expand 

c. neither a nor b

d. both a and b
Wearing Hearing Protection Properly 

15 

5. Hearing protection for very loud noise should include... 

a. high-quality, well-padded earmuffs a. high-quality, well-padded earmuffs

b. thicker foam ear plugs b. thicker foam ear plugs 

 c. ear plugs plus earmuffs c. ear plugs plus earmuffs

d. cotton in your ears plus earmuffs d. cotton in your ears plus earmuffs

6. The effectiveness of earmuffs is reduced by... 

a. long hair a. long hair 

b. glasses b. glasses 

c. long sideburns c. long sideburns 

d. both b and c d. both b and c 

 e. all of the above e. all of the above

f. none of the above f. none of the above 

7. The responsibility for wearing hearing protection rests with... 

a. your supervisor 

 b. your spouse or best friend 

c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 

a. your supervisor 

 b. your spouse or best friend 

c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker

8. The responsibility for wearing hearing protection properly rests with... 

a. your supervisor 

 b. your spouse or best friend 

c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 

a. your supervisor 

 b. your spouse or best friend 

c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 
 Wearing Hearing Protection Properly 

Appendix A: Pretest / Posttest Questions 

These pages contain the pretest / posttest questions that may be administered to the 

class or to the individual trainee. Duplicate the pages for each person in the class
Wearing Hearing Protection Properly 

1

Pretest / Posttest Questions 

Wearing Hearing Protection Properly

Directions: Circle the correct answer to each question as follows: Use the first set of 

answers (normal print) before looking at the 3-D reel (pretest), and use the second set 

of answers (italic) after looking at the 3-D reel. 

1. Which type of hearing protection is it possible to wear improperly? 

a. foam ear plugs a. foam ear plugs

b. earmuffs b. earmuffs

c. neither a nor b c. neither a nor b

d. both a and b d. both a and b

2. Before placing foam ear plugs in your ears, you should... 

a. roll them in your fingers a. roll them in your fingers

b. squeeze them with your fingers b. squeeze them with your fingers

c. roll and squeeze them c. roll and squeeze them

d. none of the above d. none of the above

3. Foam ear plugs should be inserted into your ear canals by... 

a. pushing them in with your forefinger until snug 

b. pulling up and back on ears to open up the canal 

c. neither a nor b

d. both a and b

a. pushing them in with your forefinger until snug 

b. pulling up and back on ears to open up the canal 

c. neither a nor b

d. both a and b

4. The snug fit of foam ear plugs is achieved by... 

a. inserting them into your ear as far as possible, then letting them expand 

b. holding them in with your finger until they expand 

c. neither a nor b

d. both a and b

a. inserting them into your ear as far as possible, then letting them expand 

b. holding them in with your finger until they expand 

c. neither a nor b

d. both a and b
Wearing Hearing Protection Properly 

2

5. Hearing protection for very loud noise should include... 

a. high-quality, well-padded earmuffs a. high-quality, well-padded earmuffs

b. thicker foam ear plugs b. thicker foam ear plugs 

c. ear plugs plus earmuffs c. ear plugs plus earmuffs

 d. cotton in your ears plus earmuffs d. cotton in your ears plus earmuffs

6. The effectiveness of earmuffs is reduced by... 

a. long hair a. long hair 

b. glasses b. glasses 

c. long sideburns c. long sideburns 

d. both b and c d. both b and c 

e. all of the above e. all of the above 

f. none of the above f. none of the above 

7. The responsibility for wearing hearing protection rests with... 

a. your supervisor 

 b. your spouse or best friend 

 c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 

a. your supervisor 

 b. your spouse or best friend 

 c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker

8. The responsibility for wearing hearing protection properly rests with... 

a. your supervisor 

 b. your spouse or best friend 

 c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 

a. your supervisor 

 b. your spouse or best friend 

 c. you 

 d. the manufacturer of the hearing protection 

 e. your coworker 
Delivering on the Nation’s Promise:

Safety and health at work for all people

Through research and prevention

For information about occupational safety and health topics contact NIOSH at:

1–800–35–NIOSH (1–800–356–4674)

Fax: 513–533–8573

E-mail: pubstaft@cdc.gov

www.cdc.gov/niosh

SAFER • HEALTHIER • PEOPLETM

DHHS (NIOSH) Publication No. 2005–107