Acoustic sensors play an important role in many areas, such as safety (e.g., sonar arrays), public health (e.g., ultrasonic imaging), surveillance (e.g., underwater communication and navigation), and industry (e.g., non-destructive damage detection). However, conventional acoustic sensors inevitably suffer from the fundamental pressure detection limit, which hinders the performance of current acoustic sensing technologies. Here, we design high refractive index acoustic metamaterials that have strong wave compression effect to obtain direct amplification of pressure fields in metamaterials. This enables a novel metamaterial enhanced acoustic sensing system that can help overcome the detection limit of conventional systems. Through analytical, numerical, and experimental studies, we demonstrate that this novel acoustic sensing system can help achieve over an order of magnitude enhancement in acoustic pressure detection limit. This will allow the detection of weak acoustic signals below the noise floor of the conventional acoustic sensing systems. This work is expected to impact many fronts that require high performance acoustic sensing.