In 2010, the Deepwater Horizon (DWH) oil spill had unprecedented impacts on the Gulf of Mexico ecosystem, including the twenty cetacean species inhabiting the oceanic waters of this semi-enclosed large marine ecosystem. Due to the impacts from DWH oil, restoration projects focused on oceanic cetaceans are being enacted in the Gulf, which require basic information on species' spatiotemporal density patterns, Gulf-wide movement patterns, Gulf-wide population sizes, long-term abundance trends, and species' response to oceanographic and anthropogenic processes. To address these needs, NOAA's Southeast Fisheries Science Center (SEFSC), UCSD's Scripps Institution of Oceanography (SIO), and partners initiated a comprehensive, long-term, multi-scale passive acoustic monitoring program throughout US and Mexican Gulf waters over the 2020 - 2025 period to collect data needed to develop predictive habitat models to assess the processes driving seasonal, interannual, and decadal trends in spatial distribution, density, and abundance of oceanic cetaceans. This study annually deployed moored High-frequency Acoustic Recording Package (HARP) instruments, developed, deployed, and processed by SIO on behalf of NOAA SEFSC, which led the project. These instruments continuously recorded over the 10 Hz to 10 kHz band at: A) 8 five-year long-term sites to identify temporal trends and variability at reference sites over the study period, B) 20 one-year short-term sites over a broad area of the Gulf to capture spatial trends and variability in cetacean density and environmental C) two mid-term sites for collecting data from human-made noise sources, and D) 3 six-month sites with targeted sampling using tracking arrays to obtain acoustic behavior data for density estimation.

Funding for LISTEN GoMex is provided by NOAA's RESTORE Science Program, the Deepwater Horizon Restoration Open Ocean Trustee Implementation Group, and the Office of Naval Research's Task Force Ocean.

This dataset includes raw acoustic recordings from each annual LISTEN GoMex HARP deployment over the 2020-2025 period, plus associated HARP deployments from the 2018-2020 period. In addition to the raw acoustic recordings, there are several associated files for these data which include calibration files (transfer functions) and Long-term Spectral Averages (LTSAs) for sound exploration and accessibility. Three readme files provide details on the acoustic recording's xwav format, LTSA format, and transfer function descriptions. All recordings are collected in UTC.

Amplitude calibration files called "transfer functions" are associated with the specific HARP equipment used to collect each acoustic recording dataset. Correct use of transfer functions is critical for providing absolute measured sound pressure received levels in standard acoustic measurement units, and for comparing signals within and between deployments. Transfer functions are estimates of a recording system's true sensitivity, and are being continuously evaluated and improved by Scripps Institution of Oceanography researchers and are subject to change without notice. Please review the Transfer_Function_readme before using this data.