Converting Audio Files to an Alexa-Friendly Format

You may need to use converter software to convert your MP3 files to the required codec version (MPEG version 2) and bit rate (48 kbps). One option for this is a command-line tool, FFmpeg. The following command converts the provided <input-file> to an MP3 file that works with the audio tag.

ffmpeg -i <input-file> -ac 2 -codec:a libmp3lame -b:a 48k -ar 16000 <output-file.mp3>

Another option is Audacity:

  1. Open the file to convert.
  2. Set the Project Rate in the lower-left corner to 16000.
  3. Click File > Export Audio and change the Save as type to MP3 Files.
  4. Click Options, set the Quality to 48 kbps and the Bit Rate Mode to Constant.

This requires the Lame library, which can be found at: http://lame.buanzo.org/#lamewindl.