A tactile sound speaker transmits sound-generated vibrations to a user through a touchpad to provide a tactile sound experience. The developer removal member is in contact with an adherend to which developer adheres and removes the developer from the adherend. , and if the selected compound is CF3CHFCl, said gaseous composition comprises both CF3CHCl2 and CF3CHF2 and the mole fraction of the selected compound relative to the other two compounds in said gaseous composition is less than its equilibrium amount at 500 C.