Earplug with stiffener

A method for forming an earplug that has an axis and that can be easily inserted into the ear canal and radially compressed during such insertion, to block noise, comprising:

• molding a second elastomeric material around a tube of a first elastomeric material, wherein said first material has a greater rigidity than said second material;
• molding a third elastomeric material in the inside of said tube, wherein said first material has a greater rigidity than said third material.

Earplug apparatus for lying in a human ear canal, comprising:

• a body of elastomeric first material with a front portion to be compressed in diameter as it is pushed into the ear canal to block sound, and a rear end, said body having an axis;
• a stiffener of material more rigid than said first material and of smaller outside diameter than said front portion, said stiffener lying in said body and extending along said axis to stiffen said earplug against column type collapse when said earplug is pushed into the ear canal;
• said stiffener being in the form of a tube filled with elastomeric material that is more resilient than material of said tube.

Earplug apparatus for lying in a human ear, comprising:

• a plurality of identical earplugs that lie in series with one another
• each of said earplugs comprises a body of elastomeric first material with a front portion to be compressed in diameter as it is pushed into the ear canal to block sound, and a rear end, said body having an axis and a stiffener of material more rigid than said first material and of smaller outside diameter than said front portion, said stiffener being in the form of a tube and lying in said body and extending along said axis to stiffen said earplug against column type collapse when said earplug is pushed into the ear canal;
• said tube stiffener extending continuously in series between said earplugs but with the bodies of adjacent earplugs being substantially separated from one another.

Earplug apparatus for lying in a human ear canal comprising:

• a body of elastomeric first material with a largely cylindrical front portion to be compressed in diameter as it is pushed into the ear canal to block sound, and a rear end, said body having an axis;
• a stiffener of material more rigid than said first material and of smaller outside diameter than said front portion, said stiffener being in the form of a tube and lying in said body and extending along said axis to stiffen said earplug against column type collapse when said earplug is pushed into the ear canal;
• said front portion outside diameter is at least 9.4 mm and said tube has a constant outside diameter of between 2 mm and 7 mm.

Earplug apparatus for lying in a human ear canal, comprising:

• a body of elastomeric resilient foam first material that has multiple gas bubbles, said body having a front portion to be compressed in diameter as it is pushed into the ear canal to block sound, and a rear end, said body having an axis;
• a stiffener of material more rigid than said first material and of smaller outside diameter than said front portion, said stiffener lying in said body and extending along said axis to stiffen said earplug against column type collapse when said earplug is pushed into the ear canal;
• said stiffener being in the form of a tube of a second elastomeric material that is substantially devoid of gas bubbles and which has more than twice the stiffness of said first material.