Bill, You may be interested in <a href = "http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000A5460000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0";>this</a> discussion; If I'm not mistaken a psophometric filter is the same as the CCITT filter.
It comes down to having the correct shape of the filter and apply it to the FFT data. Hope this helps. Regards, Juan Carlos N.I.
