Recurrent neural networks (RNNs), including long short-term memory (LSTM) RNNs, have produced state-of-the-art results on a variety of speech recognition tasks. However, these models are often too large in size for deployment on mobile devices with memory and latency constraints. In this work, we study mechanisms for learning compact RNNs and LSTMs via low-rank factorizations and parameter sharing schemes. Our goal is to investigate redundancies in recurrent architectures where compression can be admitted without losing performance. A hybrid strategy of using structured matrices in the bottom layers and shared low-rank factors on the top layers is found to be particularly effective, reducing the parameters of a standard LSTM by 75%, at a small cost of 0.3% increase in WER, on a 2,000-hr English Voice Search task.
For example, the usage of the Toeplitzlike structured matrices in REF gave up to 40% compression of RNN for voice search task.
Learning compact recurrent neural networks
2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Computer Science Mathematics