| 摘要 |
PURPOSE:To realize transmission functions 1 met to indivial persons' sound pressure frequency characteristics and phase characteristics by providing through- holes having mass reactances to an outer shell and making acoustic circuits variable. CONSTITUTION:An outer shell 20, through-holes (a), diaphragm 16, rear cavity (b), outer shell 23 and through-holes (b) acting as acoustic pipe given with mass reactances are provided. Here, as a rotary knob 25 is rotated, the through-holes b24 and the holes of a rotary plate 26 overlap and when the holes are open, the through-holes b24 and the holes of the rotary plate 26 overlap half, and when the holes are half-open, the positions of the through-holes b24 and the holes of the rotary plate 26 deviate and when the holes are closed, whereby the sound pressure frequency characteristics and phase characteristics may be changed from those cases. |
