Thank you Jose, what did you mean "user mode audio I/O hook"? Did you mean hook win32 api waviXXXX? Could you please give me more detais? This feature is the main feature of my new product. Thank you very much. ----- Original Message ----- From: Jose Catena To: wdmaudiodev@xxxxxxxxxxxxx Sent: Friday, June 26, 2009 2:00 PM Subject: [wdmaudiodev] Re: How to filter microphone voice? Just one more request that would benefit from a user mode audio I/O hook. Is such a thing in some list of future features to consider? If such a list exists, this should be there with a high rank, IMO. Jose Catena DIGIWAVES S.L.