Why does the Mp3 play at double speed in my copy of Windows Media Player?
I only recently found out about this particular problem. Depending upon the sound card in the computer, some versions of Windows Media Player do not handle all MP3 codecs correctly. You may be able to halve the speed by pressing rewind. Otherwise try a different media player, or better yet don’t use your PC for playing the audio at all. MP3 players are a better choice.