Composite adsorbent beads have a porous and non-adsorbent core comprising at least one inorganic material and a porous and adsorbent shell comprising at least one adsorbent layer comprising a porous adsorbent material on the surface of the core. The hearing device can have two microphones, a processing unit, and a speaker unit. In the region of the crimped part a supplementary space is provided that is open to the interior of the shield and into which at least a certain region of the proximal burner connector extends. This capability may permit the full-speed, bit-exact, testing, of both locally and remotely situated media encoders and decoders. A phosphor layer can be prepared using BaMgAlxOy:Mn alone, which is a green phosphor used in a plasma display panel, or using a mixture of BaMgAlxOy:Mn and Zn2SiO4:Mn, and a plasma display panel including the phosphor layer formed of the green phosphor has improved luminance maintenance rate and color purity.