Patent Publication Number: US-3875592-A

Title: Sound attenuating earcup

Description:
Aileo Apr. 8, 1975 SOUND ATTENUATING EARCUP [75] Inventor: Jackson A. Aileo, Carbondale. Pa  
 [73] Assignee: Gentex Corporation, New York,  
 [221 Filed: Jan. 10, 1973 [21] Appl. No.: 322,525  
 [52] US. Cl 2/209; 179/182 R 1511 Int. Cl H04r H10 (58] Field of Search 2/209. 6; 179/182 R [561 References Cited UNITED STATES PATENTS 2,46l1 721 4/1949 Volkmann 7. 179/182 R 2.858.544 11/1958 Roth 1 2/209 3.112.005 11/1963 Shaw et 11.. 179/182 R 3.231.688 l/l966 Ugarteehea. 179/182 R 3,477,067 1 H1969 Aileo 1 2/209 3.593.341 7/1971 Aileo 1 1 1 .1 2/209 3.644939 2/1972 Bcguin 2/209 3.661.225 5/1972 Anderson 1 1 1 1 .1 2/6 X D42.295 3/1912 Pape 179/182 X FOREIGN PATENTS OR APPLICATIONS 636 1150 5/1950 United Kingdom 179/182 R Primary Examiner-Werner H. Schroeder Assistant Examiner-Peter Nerbun Attorney, Agent, or FirmShenier &amp; O&#39;Connor [57] ABSTRACT A sound attenuating earcup assembly in which a rigid hemi-ellipsoidal cup formed with internal ribs and corresponding external grooves extending outwardly from adjacent to the center of the cup is provided with a generally inwardly extending ear aperture-forming surface which is closely complementarily contoured to the surface of a wearer&#39;s head surrounding his ear and in which auniformly thick. relatively thin resilient scaling pad is encased in a sealing pad envelope having a head engaging surface contoured like the cup surface and assembled over the surface to form a highly effective seal with the wearers head at all points around his ear and with the aperture-forming surface closely adjacent to the wearer&#39;s head at all 10- cations around the ear.  
 19 Claims, 21 Drawing Figures PATENTEUAPR 8|975 SHIT 1 [1F 6 PATENTEUAPR 81% 3,875,592  
 sum 3 OF 6 Fig 15 PATENTEB 3 3 87 5 59 2 sum u m g ATENIEDAPR ems SHEET 5 OF 6 SOUND ATTENUATING EARCUP BACKGROUND OF THE INVENTION There are known in the prior art assemblies for protecting the wearer against the harmful effects of high levels of ambient noise. For example. workers at airfields handling modern jet airplanes are provided with earcups for protecting their ears against high levels of ambient noise. In adddition to performing the function of protecting the wearer against ear damage resulting from such noise. these assemblies are useful in applica tions wherein the user is required to receive voice communications through earphones disposed in the cups. In some other applications the carcups may be required to be used in combination with protective helmets.  
  Most ofthe earcups ofthc prior art employ relatively rigid cups adapted to be supported in position over the wearers car. In order that these cups function effectively means is provided for forming a seal with the wearer&#39;s head in the region around his car. For this purpose. a relatively soft resilient pad is provided on the cup around the ear aperture. In order that an effective seal be provided at all locations around the ear. some pressure must be exerted on the cup against the wearers head. If a relatively thin pad of material is used, a relatively great pressure must be exerted to afford an effective seal at all points. Such a pressure often causes excessive discomfort to the wearer. Alternatively. relatively thicker pads have been employed to provide an effective seal with less pressure. The relatively soft resilient sealing material is not as effective a sound attenuator as is the relatively rigid cup structure. Consequently. the thicker the pad employed the less effective is the assembly as a sound attenuator.  
  In one attempt in the prior art to solve the problem outlined above, a rigid eareup has been formed with an ear aperture of irregular configuration and with a pcripheral flange having a like irregular outline. The flange is inclined slightly from the plane of the ear opening toward the wearer&#39;s head. When employed with a sealing pad this arrangement involves the same problems as those pointed out hereinabove.  
  My prior US. Pat. No. 3.593.34l issued July 20, I971, for Sound Attenuating Earcups&#34; discloses another approach to the problem. In the arrangement disclosed in that patent. a hemi-ellipsoidal rigid eareup is provided with a plane. inwardly extending annular ear aperture-forming flange which receives a pad of resilient material which is generally contoured to the shape of the wearer&#39;s head around his ear. While the structure shown in my patent provides an effective seal entirely around the ear of the wearer. without exerting excessive pressure on the wearer&#39;s head. it is not an ideal solution to the problem. That is. while leakage of extraneous sound into the cup is minimized in the thinner areas of the seal, excessive leakage occurs in the areas in which the seal is relatively thick.  
  I have invented an improved sound attenuating earcup which overcomes the problems of eareup assemblies of the prior art pointed out hereinabove. My sound attenuating earcup provides a more effective barrier to extraneous sound than do eareup assemblies of the prior art. My improved assembly minimizes leakage of extraneous sound into the cup at substantially all locations around the wearer&#39;s ear. My improved assembly provides an effective seal at all points around the cup without excessive discomfort to the wearer.  
 SUMMARY OF THE INVENTION One object of my invention is to provide an improved sound attenuating eareup assembly which overcomes the problem of eareup assemblies of the prior art.  
  Another object of my invention is to provide an improved sound attenuating earcup assembly which forms an effective seal against extraneous sound at all locations around the ear of the wearer.  
  A further object of my invention is to provide an improved sound attenuating eareup assembly which effectively bars extraneous sound without excessive discomfort to the wearer.  
  In general my invention contemplates the provision of a relatively rigid eareup of hemi-ellipsoidal configu ration having a generally inwardly-extending rigid ear aperture-forming flange the surface of which is con toured along its extent and in cross section to the shape of the wearer&#39;s head around his ear and in which a seal ing pad receiving envelope having its head-engaging surface similarly contoured to the shape of the wearers head around the ear receives a relatively thin pad of resilient material of uniform thickness so that in use an effective seal is provided at all locations around the wearer&#39;s car by means of a resilient pad which retains its uniformity of thickness in use and in which the relatively rigid contoured surface is close to the wearers head at all locations around the ear.  
 BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings to which reference is made in the instant specification and in which like reference numerals are used to indicate the like parts in the various views:  
  FIG. I is a fragmentary side elevation of the portion of the human head surrounding the ear.  
  FIG. 2 is an exterior plan view of one portion of my improved sound attenuating eareup assembly.  
  FIG. 3 is an interior plan view of the portion of my improved sound attenuating eareup assembly shown in FIG. 2. I  
  FIG. 4 is a rear elevation of the portion of my improved sound attenuating earcup assembly illustrated in FIGS. 2 and 3.  
  FIG. 5 is a sectional view of the portion of my im proved sound attenuating eareup assembly illustrated in FIG. 3 and taken along the line 55 thereof.  
  FIG. 6 is a sectional view of the portion of the form of my improved sound attenuating eareup assembly illustrated in FIG. 3 and taken along the line 6-6 thereof.  
  FIG. 7 is a section view of the form of my improved sound attenuating earcup assembly illustrated in FIG. 3 taken along the line 77 thereof.  
  FIG. 8 is a sectional view of the form of my improved sound attenuating eareup assembly illustrated in FIG. 3 and taken along the line 88 thereof.  
  FIG. 9 is a front elevation of a completed right hand sound attenuating eareup.  
  FIG. 10 is an interior elevation of the form of my improved right hand sound attenuating earcup assembly illustrated in FIG. 9.  
  FIG. 11 is a sectional view of the form of my sound attenuating eareup assembly illustrated in FIG. [0 taken along the line 11-11 thereof.  
  FIG. 12 is a fragmentary sectional view of the form of my improved sound attenuating eareup assembly illustrated in FIG. taken along the line I2l2 thereof.  
  FIG. 13 is a fragmentary sectional view of the form of my improved sound attenuating earcup assembly illustrated in FIG. 10 taken along the line I313 thereof.  
 FIG. 14 is a plane view from the inside of the shell.  
 and flange assembly of an alternate form of my sound attenuating earcup assembly.  
  FIG. 15 is a sectional view of the form of my sound attenuating earcup illustrated in FIG. 14 taken along the line I515 thereof.  
  FIG. 16 is a sectional view of the form of my sound attenuating earcup illustrated in FIG. 14 taken along the line I6I6 thereof.  
  FIG. 17 is an outside plan view of the form of my sound attenuating earcup illustrated in FIG. 14.  
  FIG. 18 is a fragmentary sectional view of the form of my sound attenuating earcup illustrated in FIG. 14 taken along the line l8-l8 thereof and showing the sealing pad in use with the earcup.  
  FIG. I9 is a plan view from the inside of a further form of my cup and flange forming assembly of my sound attenuating earcup.  
 FIG. is a sectional view of the form of shell and flange forming member illustrated in FIG. 19 taken along the line 2020 thereof.  
  FIG. 21 is a plan view from the outside of the shell and flange forming member assembly illustrated in FIG. 19.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 of the drawings, 1 have shown a fragmentary portion indicated generally by the reference character I0 ofthc human head in the ear region thereof. Studies have shown that the head configw ration which will be described hereinbelow is typical of about 85% of human heads. Beginning at a point just below and slightly forward of the ear 12 the mandible l4 protrudes in front ofa relatively deep hollow 16 immediately behind the mandible I4. Proceeding in the direction of the arrow A in FIG. 1, the head gradually tapers outwardly toward the mastoid process 18 of the temporal bone 20 of the head. Forward of the mastoid process 18 and slightly in front of and above the ear there is a shallow recess 22 leading into the slightly protruding rear portion of the maxilla region 24. From the maxillia 24 the face tapers slightly outwardly to the mandible region 14. In addition to the configuration thus far described, there is a small hollow 26 immediately forward of the tregus of the ear.  
  The studies referred to above further have shown that the prominence at the rear of the mandible 24 is somewhat higher than the prominence of the mastoid region 18. Moreover, the hollow l6 behind the mandible is deeper than is the hollow 22 immediately above the maxilla region 24.  
  Referring now to FIGS. 2 to 8, my improved sound attenuating earcup assembly includes a subassembly indicated generally by the reference character 28 formed of relatively rigid material such, for example, as a relatively rigid injection molded polyvinyl chloride resin. The subassembly 28 includes a hemi-ellipsoidal shell 30 formed with inner ribs 32 which extend generally radially outwardly from a point adjacent the center of the shell 30 toward the periphery thereof. These ribs are molded concurrently with corresponding grooves 34 in the outer surface of the shell 32. As will be explained more fully hereinbelow. these ribs and grooves further enhance the sound attenuating properties of the shell 30. If desired, I may apply a piece of Velcro&#34; which may be of either the hook or the eye type of the outer surface of the shell 30 to permit it to be detachably secured to a helmet or the like. Velcro is the registered trade mark of American Velcro Co. for an interengageable releasable means for securing members each to the other.  
  The assembly 28 further includes an ear aperture forming member 38 having a surface 40 which, as will be explained in greater detail hereinbelow is contoured in a manner complementary to the surface of the wearers head round his car as described hereinabove in connection with FIG. 1. Member 38 is formed with an aperture 42 surrounded by an inner reinforcing flange 44. I provide an outer peripheral flange 46 on the member 38 with a slightly offset lip 48 forming a shoulder 50 running around the inner edge of the flange 46. This member 38 is so formed that the lower edge of the lip 48 and the lower edge of the inner flange 44 lie in the same plane.  
  The shell 30 and the member 38 are assembled by setting the edge of the shell against the shoulder 50 and cementing the lip 48 to the shell by the use of any suitable adhesive known to the art.  
  As I have pointed out hereinabove, I so mold the member 38 as to contour the surface 40 to the configuration of the portion of the human head surrounding the ear. as will be seen from the description hereinbelow. and from the drawings, it will be seen that 1 contour the surface 40 not only in a direction around the periphery of the subassembly 28 but also in cross section. Beginning in region 52, I provide a mandible region recess which is relatively deeper at the outer periphery but which is only slightly contoured in the cross section. From the region 52 in the direction of the arrow B in FIG. 3, I provide a protrusion 54 adapted to be received in the hollow I6 behind the mandible region I4 of the wearers head. From the protrusion 54 the surface 40 tapers downwardly toward a mastoid recess region 56 whereat the surface tapers inwardly and is slightly concave. From the mastoid recess, the surface flows smoothly into a relatively shallow temporal protrusion region 58 adapted to be received in the slight depression 22 above and slightly in front of the ear of the wearer. From FIGS. 4 to 6 it can be seen that the height h of protrusion 54 is greater than the height a of protrusion 58. From region 58 the outer periphery of the surface moves smoothly downwardly into the mandible region recess 52. However, at the inner periphery of the surface, there is provided a slight protrusion 60 adapted to be received in the hollow 26 just in front of the tregus of the ear. From the structure just described, it will be seen that the surface 40 is extremely closely complementarily contoured to the configuration of the wearers head in the region around his ear adapted to be engaged by the resilient sealing means to be described hereinbelow.  
  My assembly includes a sealing envelope indicated generally by the reference character 62 which is vacuum formed with inner and outer walls 64 and 66 extending from a base 68 lying in a plane to a top 70. The respective heights of the inner and outer walls vary around the periphery of the envelope 62 in such a way that the surface of the top conforms generally to the configuration of the wearers head around the ear. In forming the envelope 62. a soft vinyl material first is drawn up into an upper mold and later is sealed with the flat planar base 68. I also provide the envelope 62 with a downwardly extending flange 72 around the periphery thereof to permit the envelope to be assembled over the member 38. A lip 76 around the lower edge of the flange assists in retaining the envelope in place on the member 38. Before applying the base 68 to the envelope I insert a softly resilient body 76 of suitable foamed material in the envelope. It is to be noted that the body 76 has a uniform thickness therearound.  
  In making my sound attenuating earcup l first form the shell 30 and the member 38 which provides the contoured surface 40. These members may be molded by any suitable technique known to the art from a relatively rigid synthetic resin. After the two members have been formed the cup 30 is assembled with the member 38 with the rim of the cup engaging shoulder 50 and the two members are cemented together. It will readily be appreciated that a left hand and a right hand earcup must be made to comprise a pair. The envelope 62 is then vacuum-formed from a suitable flexible material such as polyvinyl chloride. In the course of forming this member the inner and outer walls 64 and 66 are so drawn as to provide a wall 38 shaped to the configuration ofthe wearer&#39;s head around his ear. After the walls 64. 66 and 68 have been drawn. a plane inner wall is sealed to the assembly to encase the resilient body 76. At the same time. I provide peripheral flange 72 and the bead 74 which facilitate assembly of the sealing structure onto the assembly of the cup 30 and member 38. Once a pair of left and right hand assemblies have been made in the manner described, they can be applied to any suitable structure adapted to support them in position on the wearers head.  
  Referring now to FIGS. I4 to 18. in an alternate form of my sound attenuating earcup assembly. the shell 80 has a central somewhat flat portion 82 and a plurality of sides 84. 86, 88. 90 and 92, each of which includes a somewhat flattened portion adjacent to central portion 82 and leading into a curved portion the edge of which forms a smoothly curved shell periphery with the edges of the other sides. I provide such a number of sides and join the sides along their edges at an angle so that no two of the sides 84. 86, 88. 90 and 92 face each other. I have discovered that this construction affords greater attenuation for a smaller volume. It is to be noted that while I have shown this form of my cup as being relatively deep and thus enclosing a relatively great volume, in actual practice it need not be made so deep and the construction with no two sides parallel to each other will afford effective attenuation for a relatively small volume. The manner in which the sides are joined at the edges provides a plurality of external riblike bosses 94. In addition to these external rib-like bosses 94, preferably I provide the assembly with inter nal ribs 96 extending along the lines of the outer riblike bosses 94.  
  This form of my sound attenuating earcup assembly includes a flange-forming member indicated generally by the reference character 98 formed with an internal annular shoulder 99 for receiving the edge of the shell 80. Any suitable adhesive may be employed to hold flange-forming member 98 in assembled relationship with the shell 80. Member 98 includes a peripheral wall portion I00 having a height which varies in the same manner as does the height of the wall portion 38 of the form of my invention shown in FIGS. I to 13. so that the flange portion 102 has a suurface contour around the assembly which closely conforms to the configuration of the wearers head. It is to be noted in this form of my invention that the flange-forming portion I02 has a convex contour so to form a relatively larger opening I04 than does the flange in the form of my inven tion illustrated in FIGS. I to 13. I have discovered that this relatively larger opening 104 further enhances the sound attenuation provided by the assembly.  
  The particular assembly I have illustrated in FIGS. I4 to 18 is a top left earcup assembly. As can readily be seen from FIG. 14. the flange 102 has a mandible recess I06 in its lower right hand portion. a protrusion I08 in its lower left hand portion, a mastoid process recess I10 in its upper left hand portion and a temporal protrusion H2 in its upper right hand portion. Thus. as is true with the form of my invention illustrated in FIGS. 1 to 13, flange 102 is closely contoured to the configuration of the wearers head around his ear.  
  I use the same sealing envelope 62 and soft insert 76 in the form of my invention illustrated in FIGS. 14 to I8 as in the form shown in FIGS. 1 to 13. FIG. 18 illustrates the manner in which the envelope 62 and insert 76 cooperate with the assembly of shell 80 and flange forming member 98. When applied to the shell the envelope 62 follows the configuration of flange 102 so as to conform closely to the shape of the wearers head without changing the thickness of the insert 76 when the earcup assembly is applied to the wearers head.  
  Referring now to FIGS. 19 to 2], in yet another form of my sound attenuating earcup assembly. I provide a shell and flange forming member assembly indicated generally by the reference character 114. The assembly 114 includes a cup-like shell 116 having a smoothly contoured outside surface and having a flattened portion 118 centrally located in the inside thereof similar to the portion 82 of the cup 80. In this form of my shell, however. I provide a plurality of ribs 120, 122, I24, 126 and 128 which extend from the periphery of the cup 116 to the center thereof as is clearly shown in FIG. 19. In this form ofmy assembly I employ the same flange&#39;forming member 98 as in the form of the assem bly illustrated in FIGS. I4 to 17. It is to be noted that the member I16 is somewhat shallower than is the member 80. The depth of the cup is determined in some degree by the amount of attenuation desired. I use the same envelope and insert assembly 62 as in the other forms of my invention.  
  In use. when the earcup assemblies are applied to the wearer&#39;s head, the wall of the envelope will be brought into engagement with the surface 40 of the member 38. When this is done. there is provided a tight seal entirely around the ear of the wearer. This is provided by the body 76 of resilient material which. though slightly compressed by the pressure holding the assembly against the head. will be uniformly thick around the wearer&#39;s head and which will be uniformly dense therearound. At the same time. the surface 40 of the rigid assembly is relatively closely disposed adjacent to the wearers headv Owing to this arrangement. there is excellent and uniformly good sound attenuation at all locations around the assembly so that the entry of extraneous sound is held to a minimum. The use of the form of my invention illustrated in FIGS. 14  
 to 18 is similar to that described in connection with the form of my invention illustrated in FIGS. 1 to 13. [n the former form of the invention, however, the arrangement by virtue of which none of the sides 84, 86, 88, 90 and 92 are opposite each other affords increased attenuation as it does the larger opening formed by the convex flange 102.  
  It will be seen that l have accomplished the objects of my invention. 1 have provided a sound attenuating earcup which overcomes the defect of earcup assemblies of the prior art. My assembly provides a more ef&#39; fective barrier to the entry of extraneous sound through the seal between the hard shell and the wearers head. This resistance to the entrance of extraneous sound moreover, is uniform at all locations around the ear. I have found further that the provision of the grooves 34 in the outer surface of the cup 30 enhances the sound attenuating properties of the rigid cup. My sound attenuating earcup assembly has relatively low profile for the high degree of attenuation provided thereby. It is light in weight.  
  It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore. to be understood that my invention is not be limited to the specific details shown and described.  
 Having thus described my invention. what I claim is:  
  l. a sound attenuating earcup assembly including in combination, a hollow cup-shaped shell formed of rigid material, said shell comprising a base portion and a side wall portion extending away from said base portion to a peripheral edge thereof which faces the side of the wearers head in use of the assembly, said side wall portion and said base portion forming a space for receiving the ear of a wearer a flange of rigid material extending generally laterally from said peripheral edge and around said shell to provide a surface adapted to lie ad jaccnt to a wearer&#39;s head around his ear. said flange surface being formed with a contour varying in a direction around said shell periphery so that said flange surface relatively closely complements the surface of the wearers head adjacent to which said flange surface is adapted to lie. a pad of resilient material, and means for assembling said pad on said flange over said flange surface.  
  2. A sound attenuating earcup assembly as in claim 1 in which said flange surface has a first recess located generally in the front bottom region thereof corresponding to the rear of the wearers mandible.  
  3. A sound attenuating earcup assembly as in claim 1 in which said flange surface has a first recess located generally in the front bottom region thereof corresponding to the rear of the wearers mandible and in which said flange surface has a first prominence located generally in the rear bottom region thereof corresponding to the portion of the wearers head behind the mandible.  
  4. A sound attenuating earcup assembly as in claim 1 in which said flange surface has a first recess located generally in the front bottom region thereof corresponding to the rear of the wearer&#39;s mandible and in which said flange surface has a first prominence located generally in the rear bottom region thereofcorresponding to the portion ofthe wearers head behind the mandible and in which said flange surface has a second recess located generally in the top rear region thereof corresponding to the mastoid process of the temporal bone of the wearer&#39;s head.  
  5. A sound attenuating earcup assembly as in claim 1 in which said flange has a first recess located generally in the front bottom thereof corresponding to the rear of the wearers mandible and in which said flange surface has a first prominence located generally in the rear bottom region thereof corresponding to the portion of the wearers head behind the mandible and in which said flange surface has a second recess located generally in the top rear region thereof corresponding to the mastoid process of the temporal bone of the wearer&#39;s head and in which said flange surface has a second prominence located generally in the top front region thereof corresponding to the portion of the wearer&#39;s head in front of the ear and above the maxilla.  
  6. A sound attenuating earcup assembly as in claim 1 in which said flange has a first recess located generally in the front bottom region thereof corresponding to the rear of the wearers mandible and in which said flange surface has a first prominence located generally in the bottom rear region thereof corresponding to the portion of the wearers head behind the mandible and in which said flange surface has a second recess located generally in the top rear region thereof corresponding to the mastoid process of the temporal bone of the wearers head and in which said flange surface has a second prominence located generally in the top front region thereof corresponding to the portion of the wearers head in front of the ear and above the maxilla and in which said flange surface has a third prominence located below and adjacent to the front center region thereof at a location corresponding to the portion of the head in front of the tregus of the ear.  
  7. A sound attenuating earcup assembly as in claim 1 in which said flange is convex in cross-section.  
  8. A sound attenuating earcup assembly as in claim 1 in which said shell is formed with a plurality of sides. the arrangement being such that no two of said sides are parallel to each other.  
  9. A sound attenuating earcup assembly as in claim 1 in which said flange is continuous around said periphery and in which said flange is contoured both in the direction around said peripheral edge and in crosssection.  
  10. A sound attenuating earcup assembly as in claim 1 in which said pad assembling means comprises an envelope of flexible material for receiving said pad and means for assembling said envelope on said flange with a surface of said envelope adapted to engage the wearers head.  
  11. A sound attenuating earcup assembly as in claim 10in which said envelope surface is formed with a contour complementary to that of the wearers head around the ear and in which said pad of resilient material is uniformly thick.  
  l2. A sound attenuating earcup assembly as in claim 10 in which said flange and said envelope and said pad are generally elliptical and in which said pad is uniformly thick.  
  13. A sound attenuating earcup assembly as in claim 10 in which said envelope surface is formed with a contour varying in the direction around said periphery to conform of the wearers head around the ear.  
  14. A sound attenuating earcup assembly as in claim l in which said envelope has a planar inner wall. respective side walls and an outer wall. the heights of the respective inner and outer walls varying along the lengths of the walls to provide the outer wall with a surface contour conforming to the shape of the wearers head around the car.  
  IS. A sound attenuating earcup assembly including in combination. a shell formed of rigid material. said shell comprising a base portion and a side wall portion extending away from said base portion to a peripheral edge thereof which faces the side of the wearers head in use of the assembly, said side wall portion and said base portion forming a space for receiving the ear of a wearer, a flange of rigid material extending inwardly from and around said peripheral edge to provide a surface adapted to lie adjacent to a wearers head around his ear, said flange surface being formed with a contour varying in a direction around said shell peripheral edge so that said flange surface relatively closely complements the surface of the wearer&#39;s head adjacent to which said flange surface is adapted to lie, an envelope of flexible material adapted to be assembled on said flange over said flange surface around said periphery. said envelope having a surface adapted to engage the wearers head around the ear, said envelope surface being formed with a contour varying in a direction around said shell peripheral edge so that said flange surface relatively closely complements the surface of the wearers head around the ear and a uniformly thick pad of resilient material enclosed with said envelope.  
  16. A sound attenuating earcup assembly as in claim 15 in which said flange surface is contoured both in the direction of its length and in cross-section.  
  17. A sound attenuating earcup assembly as in claim 15 in which said cup is formed with internal ribs and corresponding external grooves.  
  18. A sound attenuating earcup assembly as in claim 15 in which said flange is convex in cross-section.  
  19. A sound attenuating earcup assembly as in claim 15 in which said shell is formed with a plurality of sides. the arrangement being such that no two of said sides are parallel to each other.  
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