http://www.bing.com/videos/search?q=how+to+remove+50hz+hum+from+a+recording&qpvt=how+to+remove+50hz+hum+from+a+recording&view=detail&mid=3A18B88A78442BEBFC2A3A18B88A78442BEBFC2A&FORM=VRDGAR There is a little video here kia cat. Isotope is an alternative to Audacity.
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.