Historia De Los Tapones Auditivos

History and Development of
the E•A•R® Foam Earplug

E•A•R 94-10/HP

R. Gardner, Jr.
E. H. Berger, M.S.

Aearo Company
E•A•RCALSM Laboratory
7911 Zionsville Road
Indianapolis, IN 46268-1657
phone: 317-692-1111
fax:
317-692-3116
email: eberger@compuserve.com

September 8, 1994

Version 2.4 (updated December 2004)

An invited paper presented at the 127th Meeting of theAcoustical Society of America, Boston, MA
J. Acoust. Soc. Am. Vol. 95(5), Pt. 2, May 1994, p. 2914.

ABSTRACT
What does one do with a new vinyl material that has exceptionally high energy absorption
characteristics? Noise, vibration, and shock control come to mind. If the material can also be foamed
and is safe for dermal contact, even broader applications could be anticipated. But, making it intoa
hearing protector - that's a step that no one took seriously until the first author of this paper, a chemist
who drew on lessons learned through association with an acoustical consultant, decided to try making
earplugs. His early work at National Research Corporation in the late 1960s, which he continued in the
early 1970s after his research group was purchased by Cabot Corporation, led tothe development of an
exciting hearing protector, the E•A•R® foam earplug. This earplug, commercially introduced in 1972,
which provides an exceptional combination of comfort and attenuation, rapidly became the world's bestselling hearing protector, spawning numerous imitators and patent litigation in 10 countries. The authors
will share the story of the inception and development of this productas well as some of the concepts
behind its success.
TABLE OF CONTENTS
INTRODUCTION

1

A CONCEPT IS GERMINATED

1

SELLING HIS IDEA

2

PATENTING THE FOAM EARPLUG

2

NOVEL AND UNEXPECTED

3

EARLY PRODUCTION AND SALES

4

THE "TRADEMARKED" PACKAGE

5

EARLY "TESTIMONIALS" AND PRODUCT MODIFICATIONS

5

PROVIDING MORE THAN JUST AN EARPLUG

6

WHY WAS THEE-A-R PLUG SO SUCCESSFUL?

6

A WORD ABOUT VINYL VS. URETHANE, AND THE EARLY IMITATORS

7

E•A•R PLUGS HAVE BECOME THE "STANDARD

7

THE E•A•R PLUG IN THE 1990S

8

REFERENCES

9

Figure 1 Figure 2 Figure 3 -

The only ear our Plugs won't fit
The Industrial Ear
The Standard

INTRODUCTION
The story begins in the mid 1960s at the National Research Corporation. NationalResearch, with a
string of successful developments under its belt, including the first commercial process for producing
penicillin, the first instant coffee, and the first frozen orange juice, was purchased by Norton Co. The new
Norton Research Corporation (NRC) expanded its investigative horizons with the creation of an
innovative Materials Research Group under the leadership of one of theirbrightest scientists. The group,
although small in numbers, worked on diverse projects such as encapsulation of exotic solid rocket
propellants, polymerization of diamond, production of room-temperature superconductors, instant-cure
lane-marking paint, and a new generation of joint sealants. The last of these initiatives, the joint-sealant
project, which was amongst those assigned to a young chemistnamed Ross Gardner Jr., was the
unlikely genesis of what later came to be known as the E•A•R® Plug.
In 1967, while immersed in his work, Ross noticed that the joint sealants he was developing possessed
unusual energy-absorbing properties. As a result, he asked for and was given the assignment to begin
work on an internal energy-absorbing-resins project, the description of which later becamethe basis for
the acronym "E•A•R." Ross developed a series of materials, based upon epoxies, hybrid epoxy/vinyls,
and vinyls (polyvinyl chloride). The first of the materials that found its way to the marketplace was the
"blue stuff," a highly-damped vinyl dubbed C-1002, still successfully sold today by the E•A•R/Specialty
Composites Group of Aearo Company (formerly Cabot Safety Corporation)....