Hebbian feature discovery improves classifier efficiency

Two neural network implementations of principal component analysis (PCA) are used to reduce the dimension of speech signals. The compressed signals are then used to train a feedforward classification network for vowel recognition. A comparison is made of classification performance, network size, and training time for networks trained with both compressed and uncompressed data. Results show that a significant reduction in training time, fivefold in the present case, can be achieved without a sacrifice in classifier accuracy. This reduction includes the time required to train the compression network. Thus, dimension reduction, as performed by unsupervised neural networks, is a viable tool for enhancing the efficiency of neural classifiers.