Abstract: A fuel cell system includes a fuel cell, an auxiliary unit, a sound volume acquisition unit, and a control unit. The fuel cell supplies an electric power to a sound generating device that generates a sound. The auxiliary unit allows the fuel cell to generate the electric power. The sound volume acquisition unit acquires information that is related to at least one of the volume of the sound that is generated by the sound generating device and the volume of an environmental sound. The control unit controls the operations of the auxiliary unit, based on the information acquired by the sound volume acquisition unit.

Abstract: A supporting system is provided on a saxophone for offering assistance to the player, and includes pressure sensors monitoring the touch pieces of the keys, power assisting units equipped with torque motors provided for the keys and a controller connected to the pressure sensors and the power assisting units; a conversion table for depressed touch pieces and another conversion table for released touch pieces are prepared in the controller, and different relations between the finger force and the amount of current to be supplied to the torque motor are respectively defined in the conversion tables, respectively; the amount of current to be supplied is read out from the conversion tables depending upon the increase and decrease of finger force so that the player quickly closes the tone whole with the padded cup without curious key touch.

Abstract: In order to realize a small and light key actuating apparatus for actuating a key which is rotatably supported with respect to a frame, a key actuating apparatus (7) is provided which includes a polymer transducer (9) for rotatably moving the key (3) by using a deformation of the transducer, wherein the transducer which is substantially formed in a plate shape includes: a polymer film (15) which is dielectric and made from an elastically deformable polymer material; and a pair of electrodes (17) arranged at both sides of surfaces of the polymer film, and the transducer is deformed corresponding to switching between an application of voltage and a lack of voltage between the electrodes.

Abstract: A key actuating system (1) of a keyboard musical instrument is provided which helps quickly push the keys by reducing reaction force with respect to force of pushing the keys during manual operation, and which supports a person having less strength to play the keyboard musical instrument. The key actuating system for a keyboard musical instrument generates a sound when a key (3) is pushed including: a pressure detection sensor (11) detecting a pushing pressure on the key; a status detection sensor (13) detecting a movement status of the key: an actuator (15) actuating the key in a pushing direction of the key; and a control portion (19), when the pressure detection sensor detects the pushing pressure and the status detection sensor detects motion of the key, controls operations of the actuator in order to maintain the detected pressure by the pressure detection sensor at a pressure threshold which is in a range larger than 0 and smaller than a pushing pressure on the key which is necessary for making a sound.

Abstract: In order to provide a sound-absorbing body which has both a thin thickness and improved sound-absorption characteristics with regard to a low tone range sounds, the sound-absorbing body (1) includes: an organic hybrid sheet (2) constituted from an organic low-molecular material which is spread in a matrix polymer; and a gastight air cell (3) which is closely provided at a backside (2a) of the organic hybrid sheet, wherein the organic hybrid sheet indicates both a sound-absorption peak of a random incidence sound-absorption coefficient at a frequency band of 400 Hz or lower and another sound-absorption peak when the organic hybrid sheet is vibrated by applying air vibration caused by sound, because of adhering the organic hybrid sheet to the gastight air cell.