"Marc Böhlen and J. T. Rinker. 2004. When code is content: experiments with a whistling machine. In Proceedings of the 12th annual ACM international conference on Multimedia (MULTIMEDIA '04). ACM, New York, NY, USA, 983-984. DOI=10.1145/1027527.1027761 http://doi.acm.org/10.1145/1027527.1027761" The Universal Whistling Machine (U.W.M) senses the presence of people in its vicinity and attracts them with a signature whistle. Given a response whistle, U.W.M. counters with its own composition, based on a time-frequency analysis of the original.

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