For a proper range of impedance argument, the acoustical wall alters the aero-work toward naught, while for another range of impedance argument, the abstract of aero-work is increased.

• 在某些声阻抗幅角范围内，气动功的改变是趋向于零气动阻尼，在 另一些幅角范围内，气动功绝对值增大。