def convert_to_wav
    if self.prompt.present? and self.prompt.queued_for_write[:original].present?
      data = File.read(self.prompt.queued_for_write[:original].path)
      if self.prompt.content_type == "audio/mp3" || self.prompt.content_type == "audio/mpeg"
        file = Util::AudioConverter.bin_audio_convert(data, "mp3", "wav")
        wavfile = Tempfile.new([self.prompt.original_filename.chomp('.mp3'), ".wav"])
      else
        file = Util::AudioConverter.bin_audio_convert(data, "wav", "wav")
        wavfile = Tempfile.new([self.prompt.original_filename.chomp('.wav'), ".wav"])
      end
      wavfile.binmode
      wavfile.write(file)
      self.prompt = wavfile
      self.prompt_file_name = Digest::MD5.hexdigest(self.prompt_file_name) + ".wav"
    end
end