SVoice: Enabling Voice Communication in Silence via Acoustic Sensing on Commodity Devices

Silent Speech Interface (SSI) has been proposed as a means of reconstructing audible speech from silent articulatory gestures for covert voice communication in public and voice assistance for the aphasic. Prior arts of SSI, either relying on wearable devices or cameras, may lead to extended contact requirements or privacy leakage risks. The recent advances in acoustic sensing have brought new opportunities for sensing gestures, but their original intention is to infer speech content for classification instead of audible speech reconstruction, resulting in the loss of some important speech information (e.g., speech rate, intonation, and emotion). In this paper, we propose , the first system that supports accurate audible speech reconstruction by analyzing the disturbance of tiny articulatory gestures on the reflected ultrasound signal. The design of introduces a new model that provides the unique mapping relationship between ultrasound and speech signals, so that the audible speech can be successfully reconstructed from the silent speech. However, establishing the mapping relationship depends on plenty of training data. Instead of the time-consuming collection of massive amounts of data for training, we construct an inverse task that constitutes a dual form with the original task to generate virtual gestures from widely available audio (e.g., phone calls) for facilitating model training. Furthermore, we introduce a fine-tuning mechanism using unlabeled data for user adaptation. We implement using a portable smartphone and evaluate it in various environments. The evaluation results show that can reconstruct speech with a (Character Error Rate) CER as low as 7.62%, and decrease the CER from 82.77% to 9.42% on new users with only 1 hour of ultrasound signals provided, which outperforms state-of-the-art acoustic-based approaches while preserving rich speech information.