. . "ments, device 2600 also includes one or more devices 2650 such as sound transducers for such applications as a hearing aid having an combined transducer-battery-amplifier device in order to provide a radio frequency-wave-rechargeable hearing aid which could be taken out of the ear at night and placed in an RF-emitting recharging stand (e.g., that of FIG. 27M), avoiding the need to replace batterie" . .