No way ? Why that ? You own the best equipped PCI-E card right now available on the market which works with Crazyscan and EBS Pro Lite. Both can show dB values and are free. You can get them here:
Download
CrazyScan.rar and
ReqLibs.rar from _http://sourceforge.net/projects/crazyscan/files/
unzip them in the same folder which you will name CrazyScan 1.0.1.57
Also unzip all the files of _http://crazycat69.narod.ru/sattelite/StreamReaderEx/StreamReaderExEx-BDA.rar inside the same folder and start CrazyScan.exe . You should be able to open it now and do your measurements.
EBS Pro Lite you can download here: _http://cjcr-soft.com/software/ebspro/
Just install and run it.