As a matter of fact, the mp3 decoder here makes a kind of seeping additional noise that is annoying especially on 40 wpm on the ARRL files, zo when I exercise I take text in my own language and put in in JustLearnMorseCode for exercising and not losing hobby acquired profiziency with age. Best wishes for 2014 to all readers and their family and beloveds. Wim PA0WV