It turns Your PC into a Digital Audio Filter. his program is not a general purpose "wave editor".
It concentrates specifically on the recovery of difficult audio. While many wave editors will do some basic filtering it is not their primary focus.
Restore old vinyl phonograph recordings (LPs, 45 RPM, even 78 RPM) or old tape recordings.
Realtime processing For Shortwave Listening (SWL).
This program can accept input from either live real time audio or prerecorded WAV audio files.
Listen to results in real time and/or save them to a WAV audio output file.
It employs advanced Digital Signal Processing (DSP) techniques to provide superior broadband filtering.
Connect the audio "Line Out" on your shortwave receiver to the "Line In" on your computer's sound card.
Then run the program to digitize the input, filter it and play it out through your computer's speakers in real time.
Removes heterodyne tones ("whistles") and other noise to create a more pleasant listening experience.
Find more about this application here