ENCODING AUDIO MP3 Best Practices There are several available tools to create mp3 audio lectures. Blackboard Collaborate virtual session is capable of generating audio mp3 files, Audacity audio editor is a free application available online, Wimba voice tools from Desire2Learn, handheld voice recorder, or other audio recording apps. Choose what works easiest for you. When creating mp3 audio lectures please consider breaking up large lectures into parts. Try to keep each part of a lecture audio file no more than 45 minutes. If you have a 2 hours audio lecture then break it into 3 parts and provide 3 links for the listeners to access. Ex: filename_part1.mp3, filename_part2.mp3, filename_part3.mp3 Audio Quality You don’t need to export mp3s to standard CD quality of 128kb rate which will keep your files larger and longer to download. Take a look at the same audio file (21 minutes in length) encoded at 128KB and 32KB. 128kb file is 4 times larger in file size, 4 times longer to download and will hardly make any noticeable difference in sound quality for an audio lecture. Please export Mp3 audios using the following export settings: Bit rate mode quality: 48kbps is good standard quality, 32kbps as the lowest with acceptable quality Channel mode: joint stereo channel Sound quality is drastically lowered if encoding below a bitrate of 32kbps. If using Audacity, these settings are available in the Mp3 options area of the export settings in the File menu. FYI On Collaborate Exports To Mp3 The Blackboard Collaborate recording tab from D2L allow you to export your recording to Mp3. Click the session to open the playback window on the right then choose the audio convert option to export to Mp3. Recordings are exported to 64kbps but may take up 2 hours before the Mp3 is available for download. Click on the same recording link in an hour to check the status of your Mp3 export.