Abstract: An acoustic system includes: a first customer-side microphone; a first counselor-side microphone; a first sound changing unit; a first loudspeaker; a second customer-side microphone; a second counselor-side microphone; and a second loudspeaker. Between the second loudspeaker and the first customer-side microphone, a first sound transmission path is provided. Also, between the second loudspeaker and the first counselor-side microphone, a second sound transmission path is provided. These sound transmission paths have substantially the same length. The first sound signal generated by the first customer-side microphone is made to have a phase substantially opposite to that of the second sound signal generated by the first counselor-side microphone, and the sound signals are added together.

Abstract: A sound absorbing panel is provided above an uppermost of soundproof panels arranged in plural stages in a vertical direction and each having a back surface opposite to a sound source side, the back surface being formed to be a sound insulating surface, the sound absorbing panel including: an outer frame body having therein an acoustic space in which a first acoustic material is provided, the outer frame body allowing formation of a partition wall separating a sound source and a surrounding area from each other, the outer frame body having, at a front and back portions thereof, sound transmitting surfaces each having multiple sound through holes allowing transfer of sound between the acoustic space and outside thereof; and a second acoustic material provided above an upper end of the outer frame body such that a peripheral surface of the second acoustic material except for a corner portion is air-permeable.

Abstract: The present invention enables reduction in, as well as low-frequency sound, high-frequency sound of diffraction sound that is to be diffracted in the vicinity of an upper end edge of an uppermost one of soundproof panels.

Abstract: An acoustic system includes: a first customer-side microphone; a first counselor-side microphone; a first sound changing unit; a first loudspeaker; a second customer-side microphone; a second counselor-side microphone; and a second loudspeaker. Between the second loudspeaker and the first customer-side microphone, a first sound transmission path is provided. Also, between the second loudspeaker and the first counselor-side microphone, a second sound transmission path is provided. These sound transmission paths have substantially the same length. The first sound signal generated by the first customer-side microphone is made to have a phase substantially opposite to that of the second sound signal generated by the first counselor-side microphone, and the sound signals are added together.

Abstract: The chemical setting receptacle comprises a receptacle body loading chemical and a lid covering the top opening of the receptacle body, wherein the lid is formed by connecting more than one vertical plate and a passage connected to a chemical loading section of the receptacle body is installed between the vertical plates. Urine and water hitting the ridge of the vertical plate separate and fall into the chemical loading section and also, urine and water entering the passage hit the side of the vertical plate and fall into the chemical loading section. Therefore, urine and water do not splash outward. The receptacle body and lid are made of decomposable plastic material containing an additive having a decomposition by microorganisms and sunlight characteristic. After the receptacle is used, the additive is naturally decomposed in a short time by activity of microorganisms and irradiation of sunlight, the plastic material collapses into a granular resin, and the receptacle loses its original form.