A hearing aid compatible mobile handset is provided with a parasitic element which is electrically connected to a groundplane of a circuit board. Damper energizes motor to move valve body distance, which is two-fold or more of distance from separated position where valve body is separated from valve seat to seated position where valve body is seated on valve seat, when flow path is blocked by moving valve body from separated position to seated position. A plurality of diagonal parity sets is computed, one diagonal parity set for each sub-array. Another LED inspection lamp has plurality of LEDs emitting electromagnetic radiation at a peak wavelength.