speaking with speaker modem and TAPI 3.0
===

I have used the following  code for dial a number with the speaker phone modem.

    private void Dial()
             {
                   TAddress addr = (TAddress)cbAddress.SelectedItem;

                   TAPIMEDIATYPES mediaType = TAPIMEDIATYPES.AUDIO;
                   if (addr.QueryMediaType(TAPIMEDIATYPES.VIDEO))
                   mediaType |= TAPIMEDIATYPES.VIDEO;

                   try
                   {
                         addr.Open(mediaType);
                   }
                   catch (TapiException ex)
                   {
                         // Invalid media mode? Try just datamodem for unimodem.
                         if (ex.ErrorCode == unchecked((int)0x80040004))
                         {
                               try 
                               { 
                                     addr.Open(TAPIMEDIATYPES.DATAMODEM); 
                               }
                               catch {}
                         }
                   }

                   // Create a call -- this should always succeed
                   currCall = addr.CreateCall(textDestination.Text, LINEADDRESSTYPES.PhoneNumber, mediaType);
             
                  if (currCall != null)
                  {
                        try
                         {
                               // Connect the call
                               currCall.Connect(false);
                         }
                         catch { }
                   }
        }

The problem is that I can not speak, that is, no sound coming, and no sound outing. But when I test the modem with the "[call station]" program to speak no problem there.
[call station]: http://www.google.com/url?q=http%3A%2F%2Fwww.imptec.com%2Fcallstation.htm&sa=D&sntz=1&usg=AFQjCNG3LbLzZ2EnXdAAZQ0P5UeZFP_wIA