A method of making an earplug (100), is disclosed. The method includes the steps of covering an elongate core (210, 310, 410) with an outer layer (220, 320, 420) that includes an unactivated foaming agent, positioning at least a portion of the outer layer in a mold (270, 370, 470), and activating the foaming agent such that a portion of the outer layer of at least a portion of the outer layer to form a sound attenuating portion (221, 321, 421) and a stem portion (222, 322, 422) bonded to the elongate core.
