Sonification of Data

What often happens to me is that I'll hear about something or hear a word that I'm sure I've never thought about before, and then very soon after that I'll hear about it again. I think to myself, well if it's this common, how come you haven't heard about it before...

One such "theme cluster" started when I was at CalTech working with the LIGO folks. A couple of the research scientists and post-docs were talking about how data streams are being broadcast into the control rooms of these experiments while data is being collected. By "broadcast," I assumed that the raw data feeds were available real-time or near real-time from the instruments. While that is the main meaning, one of the grad students said that someone has made an audio stream out of the data and that too is available to anyone who would like to listen to it. She also said that a couple of the people have been trained with simulated data to "listen for" gravitational wave detections by (or more commonly problems with the ) the instruments. Like the noise accompanying a heart rate monitor, I thought, one could engage another sense during data collection and instrument monitoring.

So I filed it away in the "cool idea" category and talked to a few people about it last Monday and Tuesday when I got back into the office. On Thursday of last week I went to an all day session which included some research presentations by our faculty. Dr. Mark Ballora, Associate Professor in Art & Music, presented on "sonification of data." So now I have a term for that thing in my "cool idea" category. As Dr. Ballora explains it, for sonification to be useful, you have to sonify the right quantity or quantities. For his thesis research, he sonified the interval between similar points (often peaks) in a heart rhythm. As Dr. Ballora's Web page says:

Here we propose a novel diagnostic method based in music technology. Digital music software is employed to transform the sequence of intervals between consecutive heartbeats into an electroacoustic soundtrack. The results show promise as a diagnostic tool and also provide the basis of an interesting musical soundscape.

When you listen Dr. Ballora's samples, you hear two distinct sounds in the NN+50NN samples (which are the ones he played for us). The NN is the interval between beats represented by one set of tones and the NN50 tones are additional sounds which occur if the interbeat variation is more than 50 ms (milliseconds). In a healthy heart, the latter happens more than I would have guessed (I guess I'll add an "I am not a physician, IANAP" to go with my "I am not a lawyer, IANAL" category). Check out samples for yourself on Dr. Ballora's Web pages. This could be a very powerful, non-invasive diagnostic tool.

File that away in your "cool idea" category!