It has recently become feasible to run personal digital assistants on phones
and other personal devices. In this paper we describe a design for a natural
language understanding system that runs on device. In comparison to a
server-based assistant, this system is more private, more reliable, faster,
more expressive, and more accurate. We describe what led to key choices about
architecture and technologies. For example, some approaches in the dialog
systems literature are difficult to maintain over time in a deployment setting.
We hope that sharing learnings from our practical experiences may help inform
future work in the research community.

近期，手机和其他个人设备上运行个人数字助手成为可能。本文描述了在设备上运行的自然语言理解系统的设计。与基于服务器的助手相比，该系统更具隐私性、可靠性、速度更快、表达能力更强且更准确。我们描述了关于架构和技术的关键选择。例如，对话系统文献中的一些方法在部署环境中难以长期维护。希望通过分享我们的实践经验，能够为未来的研究工作提供有益信息。

设备上的智能助手语言理解

Intelligent Assistant Language Understanding On Device

Personal Digital Assistants (PDAs) - such as Siri, Alexa and Google
Assistant, to name a few - play an increasingly important role to access
information and complete tasks spanning multiple domains, and by diverse groups
of users. A text-to-speech (TTS) module allows PDAs to interact in a natural,
human-like manner, and play a vital role when the interaction involves people
with visual impairments or other disabilities. To cater to the needs of a
diverse set of users, inclusive TTS is important to recognize and pronounce
correctly text in different languages and dialects. Despite great progress in
speech synthesis, the pronunciation accuracy of named entities in a
multi-lingual setting still has a large room for improvement. Existing
approaches to correct named entity (NE) mispronunciations, like retraining
Grapheme-to-Phoneme (G2P) models, or maintaining a TTS pronunciation
dictionary, require expensive annotation of the ground truth pronunciation,
which is also time consuming. In this work, we present a highly-precise,
PDA-compatible pronunciation learning framework for the task of TTS
mispronunciation detection and correction. In addition, we also propose a novel
mispronunciation detection model called DTW-SiameseNet, which employs metric
learning with a Siamese architecture for Dynamic Time Warping (DTW) with
triplet loss. We demonstrate that a locale-agnostic, privacy-preserving
solution to the problem of TTS mispronunciation detection is feasible. We
evaluate our approach on a real-world dataset, and a corpus of NE
pronunciations of an anonymized audio dataset of person names recorded by
participants from 10 different locales. Human evaluation shows our proposed
approach improves pronunciation accuracy on average by ~6% compared to strong
phoneme-based and audio-based baselines.

本研究提出了一种针对 TTS 语音合成任务中的发音错误检测和校正的高精度、适用于 PDA 的发音学习框架，同时还提出了一种基于动态时间规整技术和度量学习的发音错误检测模型 DTW-SiameseNet。结果表明，与基于音素和音频的基线相比，我们的方法平均提高了～6％ 的发音准确率，并且此方法不受语言和隐私问题的影响。