Clippers Tuesday: Micha Elsner on Speech Segmentation with Neural Nets; David King on Disambiguating Coordination Ambiguities

At Clippers Tuesday, Micha Elsner and David King will be giving practice talks for EMNLP and for the Explainable Computational Intelligence Workshop at INLG, respectively:

Speech segmentation with a neural net model of working memory
Micha Elsner and Cory Shain

We present the first unsupervised LSTM speech segmenter as a cognitive model of the acquisition of words from unsegmented input. Cognitive biases toward phonological and syntactic predictability in speech are rooted in the limitations of human memory (Baddeley et al., 1998); compressed representations are easier to acquire and retain in memory. To model the biases introduced by these memory limitations, our system uses an LSTM-based encoder-decoder with a small number of hidden units, then searches for a segmentation that minimizes autoencoding loss. Linguistically meaningful segments (e.g. words) should share regular patterns of features that facilitate decoder performance in comparison to random segmentations, and we show that our learner discovers these patterns when trained on either phoneme sequences or raw acoustics. To our knowledge, ours is the first fully unsupervised system to be able to segment both symbolic and acoustic representations of speech.

A Simple Method for Clarifying Sentences with Coordination Ambiguities
Michael White, Manjuan Duan and David King

We present a simple, broad coverage method for clarifying the meaning of sentences with coordination ambiguities, a frequent cause of parse errors. For each of the two most likely parses involving a coordination ambiguity, we produce a disambiguating paraphrase that splits the sentence in two, with one conjunct appearing in each half, so that the span of each conjunct becomes clearer. In a validation study, we show that the method enables meaning judgments to be crowd-sourced with good reliability, achieving 83% accuracy at 80% coverage.