Thanks for your suggestions.
Actually by saying internal CD player I meant CD ROM, sorry for not being specific about it.
I have muted the mixer signal. But the problem is little different may be you would like to read my mail again and give me some more suggestions.
>an internal CD player (or TV card etc) is automatically connected
>with its output signal to the output channel of the internal sound card,
>just to make its signal audible to the user.
>The real time convolver, however, itself sends its signal to the output
>channel of the sound card, to be audible as well, but expects the
>CD signal (or TV etc) as a Windows mixer INPUT signal. Thus, you
>may need to reconnect your CD player for convolution, or may
>need a second sound card, or a duplex sound card to have both
>channels running simultaneously.
>Your Windows mixer must be set to suppress the original signal,
>otherwise you hear both input and output of the convolver with a time
>Have a look a the FAQ section, EARS.