Friday, March 21, 2008

Hearing Voices

It's been a long while since my last post. Most of the reason for this is that for the last three months I've spent all of my free time working on a project called Round, which is now on exhibit at the Aldrich Contemporary Art Museum in Ridgefield, CT. Round is an audio installation, by Halsey Burgund, which solicits spoken voice contributions from visitors and uses them as part of a musical composition intended to be listened to while viewing the other exhibitions.

Visitors to the museum can pick up a wireless tablet and a pair of headphones from the front desk. The guard enters in their gender, approximate age, and the fact that they are a visitor into the device before handing it off. The device guides the user through a simple touchscreen interface asking them which exhibit and artwork they are looking at. The device then plays a music piece, composed by Halsey, along with voice comments about the chosen work of art. Users are able to limit the voices by age range, gender, and whether the comments are from the artist, curator, or another visitor.

The mechanism for playing the voice samples is perhaps the most interesting part of Round. Comments are not played in any particular order; they're not even played in their entirety but rather randomly sampled. Come to think of it there's not a whole lot about Round that isn't random. The voice clips are played for a random amount of time, starting from a random point in the clip, with a random amount of dead air between each one. The clips fade in for a random amount of time to a random volume level and then back back out for a random amount of time. There are two separate streams of voices so it's possible to hear more than one voice at a time and each stream randomly pans from left to right as the piece plays.

Round puts the museum visitor into an audio space that transcends time. When you listen to the piece you are hearing everyone who has ever been to the museum and talked about the art that you're looking at. The fading in and out and stereo panning gives the feeling that you're hearing bits of conversations as all the past visitors pass by you.

The exhibit opened this past Sunday so I took the trip down to Connecticut with Halsey, his girlfriend Laura, and an entourage of my nine most supporting friends to go to the reception. Brian's parents happen to live near the museum so Sarah, Emma, Trevor, Owen and I stayed over night. Nicolle, Jeff, Bob, and Chessie all showed up the day of.

Development for Round really came down to the wire. It wasn't until the morning before the opening that I rewrote the entire server to use Icecast rather raw TCP streams in order to make the kiosk version work. During the previous week we discovered that Halsey's commercial audio composition software was crashing if run for more than a few days. And at with just one hour to go before the opening, we discovered that inserting headphones into the device caused the mic to stop working. Now this is something we had tested throughly ahead of time and seemed to be pretty random as to whether or not it happened at all. Dealing with enumerable unforeseeable issues like these is enough to make anyone start hearing voice. Luckily for us that was our goal to begin with.

Despite our nerves, last minute hacks, and never ending surprises, the exhibit actually went really well. The visitors seemed to enjoy it and there were no major technical failures that the users knew about. I can remember my first sigh of relief coming when I saw an early group of visitors walking around the museum listening to the piece. The were listening, smiling, and looking at the art, rather than starring in frustration at a broken device. It felt really good.

After the reception Halsey and I spoke to Lisa Delgado, a reporter from Rhizome, which is an art and technology blog. She wrote an article about the piece called Guided by Voices.

As far as technical details go, Round is developed entirely in Python using GStreamer. The device we're using is Nokia N800, which I chose primarily for the fact that it runs entirely free and open source software. Having a device where one can really open up and hack the internals is pretty critical for any project that's as specialized as Round. Roundware, the software use to run the project, has been released under the GPL at

After deciding on the device Halsey ventured to send some emails around and see if Nokia might be interested in donating the devices for use at the museum. As it turns out, they did, so Halsey and I would like to extend a big thank you to Nokia for that. I'd also like to thank Owen Williams, a good friend of mine, whose knowledge of Python and GStreamer really helped me expedite my development process. To that end I'd also like to thank the good people of the GStreamer IRC channel and mailing list for their endless patients and key insights.

Finally I'd like to thank my nine awesome friends who took the time to come all the way down to the other side of Connecticut just to see our project and be supportive and Brian's parents for housing all of us for the night.