US2246736A - Ear stopper - Google Patents

Description

June 24, 1941. v, of KNUDSEN 2,246,736

EAR STOPPER Filed Aug. 13, 1938 Patented June v24, 1941 UNITED STATES PATENT OFFICE EAR sTorPER l Vern O. Knudsen, Los Angeles, Calif.

12 Claims.

rIdhis invention relates to ear stoppers and relates more particularly to ear protectors or ear stoppers for use by those who are disturbed by noises and undesirable sounds, by those who are subjected toA the detonations and excessive air disturbances of gun fire, riveting, blasting, etc., and by swimmers or others who wish to keep water or other undesirable substancesv from entering the ear canal.

Anotherl object of this invention is to provide ear stoppers embodying combinations or series of acoustical elements related and designated to provide a substantial sound transmission loss or insulation throughout a wide range of audible frequencies. Irl accordance with my invention the networks or series of acoustical elements of the stoppers may be so chosen and related as to Application August 1a, 193s, serial No. 224,759

(Cl. 12B-152) 4 is a reduced longitudinal sectional view of still provide a sound transmission loss or sound insulation characteristic comparable with that provided by the temporal bone and vother anatomical structures that surround and-embed the human internal ear or cochlea.

Another object of this invention is to provide ear stoppers that embody series of acoustical elements or impedances coupled by other acoustical impedances to constitute acoustical networks or combinations that provide the required or desired ratio between the transmitted and the incident sound energy throughout a given frequency range.

Another object of this invention is to provide ear protectors or ear stoppers of the character mentioned that embody series or pluralities of acoustical impedances in the nature of mass or inertia elements coupled by compliance type impedance elements in the form of loose couplings between the mass impedances which transmit -a minimum oi sound energy between the mass impedances.

Another object of this invention is to provide ear stoppers of the character mentioned inwhich the mass impedances are in the form of parts of similar or dissimilar materials having different sound transmission coeiilcients,l and the compliance impedances are in the nature of yielding walls or separators enclosing or defining spaces,

voids Aor gas chambers between the mass impedances.

Another object of this invention is to provide ear stoppers oi' the character mentioned that are` simple and inexpensive to manufacture.

A further object of this invention is to provide `ear stoppers of the character referred to that are another form of the invention.

In the following detailed description I will describe three typical preferred forms of the invention. It is to be understood that the invention may be varied considerably without departing from its broader principles and the invention is not to be construed as limited or restricted to the specific forms about to be described.

The` ear stopper of the present invention illustrated in Figs. 1 and 2 of the drawing may be said to comprise, generally, a yielding body I0 for` insertion in the auditory canal C, a plug Il in the `outer portion of the body I0 constituting an impedance of. the mass type and a plug or mass I2 in the inner portion of the body I0 forming a second mass impedance spaced from the plug Il.

The body I0 of the device or stopper is designed to be inserted inthe meatus or auditory canal C of the human ear. The body Il)I is an elongate tubular or hollow member preferably of suiilcient diameter to snugly ilt the canal C. In ac- Y cordance with the invention the body I0 is formed of a iiexible, yielding and resilient material such as rubber, rubber composition, rubber substitute; or the like. The outer end of the body I0 is open to receive the plug I I and the inner end of the body III may be closed, as

illustrated in the drawing. It `is preferred to make the inner end of the body I0 round or convex in external configuration to facilitate the introduction of the stopper to the auditory canal C.- In the construction illustrated the body III -has a partially sphericalenlargement I3 on its sirable to provide the best possible t in the ear canal.

The plug I I constitutes the iirstor outer inertia mass acoustical impedance element of the device, being located in the outer portion of the body I to receive the incident sound energy.A The plug II is preferably a solid or non-hollow member of brass, stainless steel; lead, bronze or similar metal or material of relatively high specific gravity. In practice the plug II may be tapered as shown to impart a similar taper to the body I0. The major portion of the plug II is inserted in the outer part of the body IIJ and is suitably secured in the body. The plug II may be cemented, vulcanized or otherwise xed in the stopper body I0. The plug II may extend outwardly beyond the end of the body I0, or it may be partially or completely surrounded by the body I0 in such a manner as to add to the comfort of wearing the device and to facilitate the insertion and removal of the stopper. -In the particular embodiment of the invention shown in Figs. 1 and 2 the projecting portion of the plug I I is enlarged in diameter and is shaped to constitute a handle or knob It that may be conveniently engaged for the purpose of inserting the stopper in the auditory canal C and for the purpose of withdrawing the stopper from the ear. If desired or believed necessary the knob 'I6 may be covered with a skin or coating I of rubber, or the like, or as shown in Fig. 3, the wall of the body III may diverge or flare outwardly and partially surround the knob I l and thus prevent the plug II from touching the ear. Such diverging wall or flange may also improve the iitl of the stopper in the ear .cana'l and may also facilitate easy removal of the stop per. spaced a considerable distance from the inner enlargementI I3 of the stopper body IU, but limitation of space in the ear canal may require a short distance.

The plug or mass I2 constitutes the second or inner mass or inertia type of acoustical impedance of the stopper. The mass I2 is provided in the inner part of the body Iii and in the structure illustrated occupies the hollow enlargement I3 of the body. The shape and proportions of the mass I2 may be such that the mass distends the yielding resilient body Ill to provide and maintain the enlargement I3, or if desired the body enlargement I3 may be preshaped or preformed to receive the mass I2, or the mass I2 may be cast or formed of the same material as is used for the body Ill in such shape as will best lt the ear canal. 'I'he parts may be related and proportioned so that the inherent resiliency of the body Ill holds the mass I2 in its proper position. If desired or believed necessary the mass I2 may be cemented, vulcanized or otherwise secured in place the body I0. It is preferred to construct the mass I2 of a yielding material such as soft rubber, sponge rubber, beeswax, or the like, so that it will not cause injury to the ear when the stopper is inserted in the auditory canal C. Owing to the fact that the mass I2 is of soft or yielding material its acoustical compliance and resistance may be substantial although the mass I2 is primarily a mass impedance.

In accordance with the invention the mass I2 is spaced from the inner end of the plug I I to leave or provide a space or chamber I B in the body I0. In practice the chamber I6 may be of substantial longitudinal extent as illustrated in the drawing. As will be evident the chamber I6 is dened or enclosed by the surrounding wall The inner end of the plug I I is preferably extending outwardly beyond the knob I 4a.

oi the body I and the opposing end surfaces of the plug II and the mass I2. The chamber I6 may' contain air or other gas or, if desired, a partial vacuum may be maintained in the chamber I6. In the event that the chamber I6 contains a gas orsin the event that a partial vacuum is maintained in the chamber the plug II is sealed in the body I8.

In the use or operation of the stopper illustrated in Figs. 1 and 2 of the drawing the stopper isinserted in the' auditory canal C to occupy a position such as illustrated in Fig'. 1. If desired the body I0 may be provided or covered with petroleum jelly, or the like, prior to the insertion of the stopper so that the stopper may readily enter the canal C. 'I'he stopper maybe allowed to remain in the ear for as long a period as required and may be removed when desired.

'I'he stopper is highly ecient in its sound insulation properties. 'Ihe dense metal plug II forms the outer acoustical impedance or mass impedance of the device. The plug II, being of dense material, has a small acceleration or displacement imparted to it by the force of the incident sound waves or explosion waves in the case of gun fire, blasting, etc. The mass I2 constitutes a second inertia or mass acoustical impedance but being of soft material mayhave an appreciable acoustical compliance and resistance. The Wall of the yielding body I0 and the chamber I6 between the plug II and the mass I2 constitute a very loose coupling between the plug and mass I2. This loose coupling is a highly eiclent acoustical compliance and resistance element and only a small fraction of sound energy communie cated to the plug I I is transmitted by the said loose coupling to the mass I2. From the above it will be apparent that the stopper of the invention shown in Figs. 1 and 2 involves two mass impedances separated by `a-iiexible coupling. vBy variation of the mass and size of the plug II, the character of the gas in the chamber I6, the dimensions of the chamber I E, the thickness and compliance of the wall of the body I 0 and the size, compliance and density of the mass I2, the sound transmission and insulating characteristics of the device or stopper may be altered to suit various conditions of use or application. 'Ihe stopper constructed as described above provides a transmission loss or sound insulation of between approximately 45 to 60 decibels throughout a. wide range of audible frequencies.

The form of the invention illustrated in Fig. 3 of the drawing is characterized by an additional or third mass impedance. The improved ear stopper of the invention illustrated in liigl 3 may be said to comprise, generally, a body Illa, a plug II a in the outer portion of the body IIIe, a mass I2a in the inner portion of the body IIIa and a partition I8 in the body I0 spaced between the plug I Ia and the mass I2a.

The body Illa may be similar to or identical with the body I 0 described above and the plug I Ia may be similar to the plug I I. In the particular case illustrated the plug I IP- is somewhat shorter than the .plug II and has a smaller knob Ita. The body I may have a ilaring flange or skirt 30 'I'he skirt` prevents contact of the knob |48 with the luser, limits insertion of the stopper in the auditory canal, assures a better t of the stopper in the canal and facilitates the removal of the stopper from the ear. The mass I2 is similar to the above described mass I2 and occupies the enlarged inner portion I3Si of the body I0, The

mass I2* is preferably formed of soft or yielding material and is provided with a central cavity I! to render it more yielding. The body III, the plug IIa and the mass I2'l may be constructed of the same materials as the body III, plug II and mass I2, respectively, of the previously described form of the invention. Furthermore,.

tween the opposing ends ofthe plug Il* and the mass I2* although the position of the partition may be varied as found desirable. 'I'he partition I8 may be constructed of any suitable material having a substantial density. Any suitable means may be employed to retain the partition I8 in the body IIIe'. In the typical arrangement illustrated the edge or peripheral portion of the partition is gripped `or received in an internal groove 22 in the wall of the body I. If desired or necessary The plug IIh is spaced some distance forwardly from the mass 82h, providing achamber lib within the body I0. Any suitable means may be employed to secure the plug I Ib in place. In the case illustrated the peripheral portion of the plug IIb is received and secured in an internal groove 22b in the body Illb.

Having described only typical preferred forms and applications of my invention, I do not wish to be limited or restricted to the speciiic details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art, or which fall within the scope of the following claims:

Having described my invention, I claim:

1.. An ear stopper of the character described comprising spaced solid matter parts forming acoustical mass impedances, said parts beingof diierent densities, and a yielding tubular body adapted to be received in the auditory canal whose end portions contain and are defined by the solid matter parts, the body constituting l an acoustical compliance coupling said parts.

the partition I8 may be cemented or vulcanized v in the groove 22.

The two chambers 20 and 2i in the body III'i may contain air or gas, or a partial vacuum may be maintained in the chambers. Cotton or wool fibre F, synthetic bre, or the like, is loosely arranged in the chambers 20 and 2l to provide a better sound insulation.

The stopper of the invention illustrated in Fig. 3 may be employed in the same manner as the previously described form of the invention. 'nie stopper shown in Fig. 3 operates in substantially the same manner as the previously described form of the invention; however, it embodies a third mass acoustical impedance, namely, the partition I8. It will be seen that the stopper of Fig. 3 embodies three inertia or mass impedances coupled by loose couplings. The three mass impedances are found in the plug Il, the partition I8 and the mass I2a and the loose couplings are found in the body wall and the chambers 20 and 2| between the spaced impedances. The loose couplings between the series of spaced mass impedances transmit a minimum of the sound energy from one mass impedance to the other and the network or system constitutes a highly efilcient sound insulation device. l

Fig. 4 of the drawing illustrates a form of the invention particularly adapted for use by swimmers and others who wish to prevent the entrance of fluids to the ears. In this form of the invention the body Il)b is -longitudinally tapered and is provided at its outer end with a flaring flange or skirt b similar to the above described skirt 30. The body I Ilb may be constructed of rubber, rubber composition, or the like, and is flexible and resilient. The inner acoustical impedance mass I2b is formed integral with the body I0". y may take the form of an internal enlargement in the inner portion of the stopper body I0. The outer acoustical impedance mass or plug I Ib is in the form of a separator or partition extending transversely across the interior of the body I0". The plug I Ib may be constructed of any suitable material, for example, it may be formed oi' the same material as the above described mass II.

As shown in the drawing the mass I2b l 2. An ear stopper of the character described comprising spaced solid matter parts forming acoustical mass impedances. one of said parts being of dense unyielding material and the other part being of less dense yielding material, and a hollow yielding body adapted to be received in the auditory canal and whose end portions contain and are defined by said parts, the body together with said parts defining a closed chamber, said body and ch-amber constituting aloose compliance coupling between said parts.

'3. An ear stopper including .a series of spaced masses having diiferent sound transmission coeillcients constituting acoustical inertia impedances, and a yieldable tubular body extending between and connecting said masses and constituting an acoustical compliance impedance coupling, said masses and the body defining closedv chambers between the masses.

4. An ear stopper including a series of spaced masses having diiferent sound transmission coefficients constituting acoustical inertia impedances, and a tubular body of yielding material carrying and connecting said masses and defining chambers between the masses, the body and said chambers forming acoustical compliance impedance couplings between the masses.

5. An ear stopper comprising an elongate hollow yieldable body adapted to be inserted in the auditory canal, a yieldable solid matter mass closing the inner end of the body and a substantially unyielding solid matter mass closing the outer end of the body and maintaining the shape of the outer portion of the body, the last named mass being spaced from the yieldable mass to leave a closed chamber in the body.

6. An ear stopper comprising an elongate hollow body of yieldable resilient material, a plug of dense solid matter material confined in one end portion of the body by the resiliency of the body, and a mass of soft solid matter material confined in the other end portion of the body in spaced relation to said plug to leave a closed space in the body.

7. An ear stopper comprising a tubular yieldable body closed at its inner end and adapted to be introduced into the auditory canal, a metal p lug in the outer portion of the body. and a soft mass in the inner portion of the body spaced from the plug, said plug and mass being spaced apart to leave a closed chamber in the body.

8. An ear stopper comprising a tubular yield- 4 Y A able body closed atits inner end. 'and adapted to be introduced intothe auditory canal, a. mass in the inner portion of the body, and a mass sealed in the outer portion of the body, one of said masses being soft and the other being of substantial density, said masses being spaced` they plug and mass to leave chambers in the bo l1. An ear stopper comprising a. tubular yieldable body to be inserted in the auditory canal, a dense plug in one end of the body, a yieldable mass in the other end of the body, a transverse partition in the body spaced from the plug and mass to leave chambers in the body, and absorptive bre in said chambers.

l2. An ear stopper comprising a tubular yieldable body closed at its inner end and adapted to be introduced into the auditory canal, a. iiaring skirt on the outer end of the bodya metal plug in the outer portion of the body, and a soft mass in the inner portion of the body spaced from the plug.

VERN O. KNUDSEN.

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