Passive Aquatic Listener (PAL) is an autonomous underwater passive acoustic recorder developed by HORST for long-term marine environmental and security monitoring.
The PAL continuously captures underwater soundscapes, detecting vessel traffic, biological activity, and other acoustic events. It is designed to operate in both stand-alone and networked configurations, providing reliable passive acoustic coverage for extended missions.
The PAL system features low power consumption, modular hydrophone options, and integrated data storage.
Its rugged housing allows for deployments in ports, coastal zones, or deep-sea observatories, making it ideal for harbor protection and environmental studies.
Each unit records sound pressure levels and can also be synchronized with other PALs to form a distributed hydrophone array.
The technology builds on the company’s long expertise in underwater acoustics and hydrophone design, following best practices used by leading research institutions such as NOAA (https://www.ncei.noaa.gov/products/ocean-acoustics) and Applied Psychoacoustics Laboratory (APL: https://apl-hud.com/)