PAMS: Improving Privacy in Audio-Based Mobile Systems

Abstract

Smartphones and mobile applications have become an integral part of our daily lives. This is reflected by the increase in mobile devices, applications, and revenue generated each year. However, this growth is being met with an increasing concern for user privacy, and there have been many incidents of privacy and data breaches related to smartphones and mobile applications in recent years. In this work, we focus on improving privacy for audio-based mobile systems. These applications will generally listen to all sounds in the environment and may record privacy-sensitive signals, such as speech, that may not be needed for the application. We present PAMS, a software development package for mobile applications. PAMS integrates a novel sound source filtering algorithm called Probabilistic Template Matching to generate a set of privacy-enhancing filters that remove extraneous sounds using learned statistical "templates"of these sounds. We demonstrate the effectiveness of PAMS by integrating it into a sleep monitoring system, with the intent to remove extraneous speech from breathing, snoring, and other sleep sounds that the system is monitoring. By comparing our PAMS enhanced sleep monitoring system with existing mobile systems, we show that PAMS can reduce speech intelligibility by up to 74.3% while maintaining similar performance in detecting sleeping sounds.