Evaluation of fast algorithms for finding the nearest neighbor

In speech recognition systems as well as in speech coders using vector quantization, the search for the nearest neighbor is a computationally intensive task. We address the problem of fast nearest neighbour search. State of the art solutions tend to approach logarithmic access time. The problem is that such performance is generally achieved at the expense of a significant increase in storage requirements. We compare several known approaches and propose new extensions. These new contributions allows for a significant reduction in memory requirements without impacting the performance in terms of number of distances computed and optimality of the search