Abstract: A chair has two vertical side pieces connected by three horizontally elongated struts. A back piece is connected between the struts and extends upwardly therefrom. A seat piece is connected between the side pieces. When adjusted in one position, the seat piece engages the first and second strut and supports the chair in a stationary position on the side pieces and the seat pieces. When adjusted to another position, the seat piece engages the first strut and the third strut and allows the chair to be supported only on the side pieces, on their curved lower edges. Thus, the chair may rock back and forth on the side pieces.

Abstract: A device for protecting the ears from loud sounds while enabling low-level voice frequency sounds to be discerned. A microphone is positioned on the outside of an insulated ear protector and a sound reproducer positioned within the protector. The sound picked up by the microphone is subjected to audio amplitude compression and voice frequency bandpass filtering before being converted back to sound.