A latch assembly is provided for a movable closure element. The device attaches to sheetrock walls through magnetic attraction to sheetrock screws or nails. The first interfering member includes a first end surface. The optical source device supplies optical energy to the optical waveguide. The system additionally executes standard AGC techniques to refine the gain for the first-time talker while the first-time talker continues speaking. The dehumidifying apparatus includes a plurality of dehumidifying devices, and is thereby capable of controlling humidity of exhausted air to a required level of humidity by removing moisture contained in air exhausted from the plurality of dehumidifying devices in multiple steps.