Voice Trigger Detection from LVCSR Hypothesis Lattices Using Bidirectional Lattice Recurrent Neural Networks
AuthorsWoojay Jeon, Leo Liu, Henry Mason
AuthorsWoojay Jeon, Leo Liu, Henry Mason
We propose a method to reduce false voice triggers of a speech-enabled personal assistant by post-processing the hypothesis lattice of a server-side large-vocabulary continuous speech recognizer (LVCSR) via a neural network. We first discuss how an estimate of the posterior probability of the trigger phrase can be obtained from the hypothesis lattice using known techniques to perform detection, then investigate a statistical model that processes the lattice in a more explicitly data-driven, discriminative manner. We propose using a Bidirectional Lattice Recurrent Neural Network (LatticeRNN) for the task, and show that it can significantly improve detection accuracy over using the 1-best result or the posterior.
A growing number of consumer devices, including smart speakers, headphones, and watches, use speech as the primary means of user input. As a result, voice trigger detection systems—a mechanism that uses voice recognition technology to control access to a particular device or feature—have become an important component of the user interaction pipeline as they signal the start of an interaction between the user and a device. Since these systems are deployed entirely on-device, several considerations inform their design, like privacy, latency, accuracy, and power consumption.