the functions of the decaying elements may be improved the dynamic range of the anti decaying character will be increased and the redundant dynamic range of the amplifier or handset will be increased generally a synthesizer can be used to perform music and can be used to perform any amplitude distributing music if the playing device is over the dynamic range to produce saturation distortion or mixed tunes distortion the price of playing device will be decreased therefore the distortion is not being wanted to produce at any position the signal processing portion of the amplifier and microphone has the compression function which can produce significant effect in addition improving the cost efficiency of the device in theory is to avoid overspecification therefore the compression function is added into the electrical circuit the compression function is not the essence of the invention the decaying element of the present invention has the excellent characters in the alt and there is a little shortcoming in the bass compressed with the alt the bass function is not prone to be controllable compared with the alt function of course it is inevitable to make up the shortcomings of the two functions and further decrease the noise the present invention can be combined to solve many problems such as problem of hardly raising active locating closed loop grain the earphone is a consumable since the each user has a.