Thursday, February 01, 2007

Audio experiment

I have recently decided to explore the option to use audio to capture, and distribute online, knowledge sharing which takes place during face to face (f2f) events. As there may be other non multi media specialists out there, who would like to enter the world of "audio capturing", I am "capturing" my own "learning by doing" process here in case it can help others (smart enough to do more research than I did) to get a jump start.


  • Some target groups are less inclined than others to use written text to share knowledge. Audio can be an alternative medium to share knowledge via the internet.
  • Also audio requires less bandwidth than video, thereby reaching those with only low bandwidth access.
  • Recording a f2f event also creates the opportunity for those unable to attend the event, to benefit by being able to listen to the discussions which took place.
  • Audio is of course not collaborative in the sense that immediate feedback and response or interaction is possible, but it can feed online collaboration with a different format of input besides written text.
  • And audio can be transcribed to text at a later date, using services provided online, but this is the next phase in my experimentation.

The beginnings, in hindsight

As the saying goes, "hindsight is 20-20" and I can clearly see now that some further preparation would have been beneficial. My advice to anyone undertaking a similar endeavour, is primarily to try it out initially in a context with no pressure to succeed. Test your hardware and software beforehand. In my defense, it was a spur of the moment decision to start my audio endeavour at the ecollaboration f2f event, so I made do with the tool I had, which was my mobile phone.

Mobile Phone

I used the speech recording functionality on my mobile phone. Only a couple minutes into the discussion did I notice that the recorder automatically ended after 5 or so minutes, so I had to keep pressing record, thereby not being able to record a full conversation without interruptions.

In the evening, once having transported my recordings via bluetooth to my laptop (another learning curve surmounted), I saw that the format of the file (mp4) was not recognized by the various multi media software options I had on my computer. Further investigation via Google taught me that I need to encode (i.e. convert) the file to a mainstream format. To do this I needed to download and install new software. The "mobile phone - audio file" endeavour has ended there for now.

Capturing audio via video

During a second (non-related) event I decided to use my digital camera, using the video option to record voices. The benefit of this approach was that I was easily able to edit the files afterwards using the visuals as memory triggers regarding the beginning and ending of sessions. So I could edit the files and provide them in sections which were intuitive for the rest of the group.

But here again, it was a learning by doing process to find out how to extract only audio from a video file. I first used the free tool, windows media encoder. The options I choose to encode the file, took almost as much time to complete the process, as the audio file was itself. So either I need to examine windows media encoder more closely, or it is not a quick tool to encode video to audio. Finally I found the option to extract only audio from the video file, using Adobe Premiere's own encoder. This went very quickly. I now have doubts however, if I have compressed the file as much as possible because I now have audio files of 50 minutes which are 23 MB large... not really a feasible option for low bandwidth usage.

Future, mp3 player

The next attempt I plan will be using my mp3 player which also has a sound recording option. Taking into consideration that the mp3 player is focussed on audio, I expect the resulting files to be smaller and therefore more practical for a target group of low bandwidth users. I also expect the files to be in a mainstream format, no or minimal encoding necessary. But this last experiment I will undertake with a purely experimental approach, not expecting to have usable files as a result.

I will keep you posted!


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