There are some known issues with Android OS powered smartphones playing .Wav files. Because there is so much fragmentation with the Android OS as well as the additional layers the carries put on top of the OS, it is difficult to pinpoint which handsets will or won't play .Wav files. THIS IS NOT an issue with the voicemail to email system we use. .Wav is a very standard audio codec and is one of of the reasons we use it. If your handset will not play the .Wav attachment or you receive "Sorry, the player does not support this type of audio file" or "Error playing the requested track" we recommend you download a .Wav player from the Android marketplace supported by your phone or contact your cellular service provider for additional help. Here are some links that explain the issue and some resolutions.