It's a bit silly to consider such an inefficient device. Not inefficient because of the electronics, inefficient because of the reciprocating motion of the magnet, the coil, the electronics, the case, the hand and even the arm... all to get a little energy into a capacitor to light a bulb.
On the other hand the handle of the crank powered radios is much more efficient with a smoother motion and less "stuff" moving.
No, trying to get useful energy from sound is difficult in all but a very few environments. In most of those environments it is not hard to find electricity anyway.