Abstract: A body-felt sound unit having a vibration transmitting member imbedded in a human body support member, for example, a chair, a bed, etc., and an electro-mechanical vibration transducer attached to the vibration transmitting member, the transducer generating mechanical vibration on receipt of a low-frequency current, thereby transmitting the vibration to the human body. The vibration transmitting member comprises a flat plate- or net-shaped member of a relatively large area, and the electro-mechanical vibration transducer is attached to the vibration transmitting member such that the direction of vibration generated from the transducer coincides with the direction of the width of the vibration transmitting member so as to transmit transverse vibration to the vibration transmitting member. Even if the vibration transmitting member is thin, the apparent rigidity becomes high, so that the transmission of vibration is made effectively.

Abstract: A sensible body vibrator has a vibration unit mounted in a human body support such as a bed or a chair and adapted to generate mechanical vibrations upon receipt of a low-frequency signal. The inputting of various kinds of signals (including a low-frequency signal from an acoustic device, a pleasant sleep signal for inducing the user to pleasant sleep, an awakening signal for generating a signal at a preset time, a signal for transmitting a routine time schedule to particularly the deaf and dumb, a security signal for detecting and announcing the entry of an intruder entering a house through a door or a window or by climbing a wall, an emergency signal for announcing an emergency situation at the time of an emergency such as a fire, and similar other signals) is selectively controlled. The emergency signal is given priority over the other signals when the emergency signal is input.

Abstract: Audio-band electromechanical vibration converter characterized in that a yoke having a permanent magnet and a magnetic gap formed therein is displaceably housed by a damper in a casing to which a vibration plate is attached; a coil attached to the casing is placed in said magnetic gap; and the casing gives an output of a mechanical vibration synchronized with a low-band audio-signal.

Abstract: Audible entertainment signals are also filtered to detect speech presence whereby only frequencies in the band 0-150 Hz, are applied to vibrate a listener's chair for special effects.

Abstract: Audio-band electromechanical vibration converter characterized in that a yoke having a magnetic pole and a magnetic gap formed therein is displaceably housed by a damper in a casing to which a vibration plate is attached; a coil attached to the casing is placed in said magnetic gap; and the casing gives an output of a mechanical vibration synchronized with a low-band audio-signal.

Abstract: A sound frequency reproduction system and apparatus has a chair for a human. A transducer is vibrated by a sound signal of appropriate frequency. The vibrating shaft of the transducer is directly fitted to the framework of the chair. The sound signal is provided to an acoustic device, including a speaker, located near the chair.