Finding Latent Sources in Recorded Music With a Shift-Invariant HDP

We present the Shift-Invariant Hierarchical Dirichlet Process (SIHDP), a nonparametric Bayesian model for modeling multiple songs in terms of a shared vocabulary of latent sound sources. The SIHDP is an extension of the Hierarchical Dirichlet Process (HDP) that explicitly models the times at which each latent component appears in each song. This extension allows us to model how sound sources evolve over time, which is critical to the human ability to recognize and interpret sounds. To make inference on large datasets possible, we develop an exact distributed Gibbs sampling algorithm to do posterior inference. We evaluate the SIHDP’s ability to model audio using a dataset of real popular music, and measure its ability to accurately find patterns in music using a set of synthesized drum loops. Ultimately, our model produces a rich representation of a set of songs consisting of a set of short sound sources and when they appear in each song.