LiquidListener: Supporting Ubiquitous Liquid Volume Sensing via Singing Sounds

Abstract

This work proposes LiquidListener, a novel liquid volume sensing method for containers. Specifically, it enables the ubiquitous measurement of liquid volume not available in existing work due to i) dependencies on dedicated sensing hardware (e.g., capacity sensors) and containers (e.g., transparent containers) and ii) a high training intensity. A key enabler of LiquidListener is listening to singing sounds. When a user taps a container using solid objects, such as pens and teaspoons, the container vibrates freely and produces a singing sound. As the container is filled with more liquid, the pitch of the sound decreases. Based on this relationship, we develop acoustic-based liquid volume sensing algorithms that support the precise measurement of liquid volume while using only a smartphone and requiring minimal user effort for calibration. The extensive experiments demonstrate that LiquidListener can support high accuracy with an average error ratio of 2.3% in sensing the liquid volume in various containers. In addition, the experimental results indicate that it can still maintain a similar level of accuracy in diverse and dynamically changing environments, even without additional calibration.INDEX TERMS Acoustic sensing, mobile healthcare services, smarthome applications, ubiquitous liquid volume sensing,