Go to the Audio page after logging in and upload your audio file.
Make sure your audio file is a wave. Format Extension: .wav
Make sure you upload in the following format:
Audio format code: 8khz_8bit_mono
If you are using Audacity do the following when saving your audio file:
File > Export > Other Uncompressed Files > Options > WAV Microsoft > Encoding > Unsigned 8 bit PCM.