PURPOSE: To obtain the superior reproducing ability of a low frequency band with a suppressed leakage sound from a canvas member by constituting the canvas member to be stretched on a frame constituting the frame of a chair by such a constitution that a network-shaped fiber is covered by a foaming synthetic resin.

CONSTITUTION: The canvas member 30 to be stretched on the frame 1 is constituted by the constitution that the meshy (net formed) fiber is covered by the foaming synthetic resin. The network-shaped fiber is constituted by an aggregate to which the warp and the weft are made of the strand of several tens of e.g., a polyester long fiber (filament), and the pitch between the warp and the weft are about 5 mm (network form of 5 mm square). The fiber which is shaped into the network form is coated by the foaming resin represented by a vinyl chloride resin, and is treated by a low foaming treatment. Thus, the occurrence of the leakage sound caused by the vibration of the canvas member is prevented, and a body sensory acoustic system with the suprior reproducing ability of the low frequency band can be obtained.