Small tip:
When I record sound on my Android smartphone the software saves audio files in the 3gp format. Unfortunately for some reasons the 3gp file settings does not let the Windows Media Player standard codecs play the recorded sound.
I found a very helpful website, which for free converts 3gp formats to mp3 for free.
I would like to recommend the website:
http://audio.online-convert.com/convert-to-mp3