@article{ragland2022,
  title = {An Overview of Ambient Sound Using {{Ocean Observatories Initiative}} Hydrophones},
  author = {Ragland, John and Schwock, Felix and Munson, Matthew and Abadi, Shima},
  year = {2022},
  month = mar,
  journal = {The Journal of the Acoustical Society of America},
  volume = {151},
  number = {3},
  pages = {2085--2100},
  publisher = {Acoustical Society of America},
  issn = {0001-4966},
  doi = {10.1121/10.0009836},
  urldate = {2022-04-04},
  abstract = {The Ocean Observatories Initiative (OOI) sensor network provides a unique opportunity to study ambient sound in the north-east Pacific Ocean. The OOI sensor network has five low frequency (Fs = 200\,Hz) and six broadband (Fs = 64 kHz) hydrophones that have been recording ambient sound since 2015. In this paper, we analyze acoustic data from 2015 to 2020 to identify prominent features that are present in the OOI acoustic dataset. Notable features in the acoustic dataset that are highlighted in this paper include volcanic and seismic activity, rain and wind noise, marine mammal vocalizations, and anthropogenic sound, such as shipping noise. For all low frequency hydrophones and four of the six broadband hydrophones, we will present long-term spectrograms, median time-series trends for different spectral bands, and different statistical metrics about the acoustic environment. We find that 6-yr acoustic trends vary, depending on the location of the hydrophone and the spectral band that is observed. Over the course of six years, increases in spectral levels are seen in some locations and spectral bands, while decreases are seen in other locations and spectral bands. Last, we discuss future areas of research to which the OOI dataset lends itself.},
  file = {/Users/john/Library/CloudStorage/OneDrive-UW/zotero_library/Ragland et al_2022_An overview of ambient sound using Ocean Observatories Initiative hydrophones.pdf}
}

@article{schwock2021d,
  title = {Characterizing Underwater Noise during Rain at the Northeast {{Pacific}} Continental Margin},
  author = {Schwock, Felix and Abadi, Shima},
  year = {2021},
  month = jun,
  journal = {The Journal of the Acoustical Society of America},
  volume = {149},
  number = {6},
  pages = {4579--4595},
  publisher = {Acoustical Society of America},
  issn = {0001-4966},
  doi = {10.1121/10.0005440},
  urldate = {2022-04-04},
  abstract = {Large scale studies of underwater noise during rain are important for assessing the ocean environment and enabling remote sensing of rain rates over the open ocean. In this study, approximately 3.5\,yrs of acoustical and meteorological data recorded at the northeast Pacific continental margin are evaluated. The acoustic data are recorded at a sampling rate of 64\,kHz and depths of 81 and 581\,m at the continental shelf and slope, respectively. Rain rates and wind speeds are provided by surface buoys located in the vicinity of each hydrophone. Average power spectra have been computed for different rain rates and wind speeds, and linear and nonlinear regression have been performed. The main findings are (1) the linear regression slopes highly depends on the frequency range, rain rate, wind speed, and measurement depth; (2) noise levels during rain between 200\,Hz and 10\,kHz significantly increase with increasing wind speed; and (3) the highest correlation between the spectral level and rain rate occurs at 13\,kHz, thus, coinciding with the spectral peak due to small raindrops. The results of this study indicate that previously proposed algorithms for estimating rain rates from acoustic data are not universally applicable but rather have to be adapted for different locations.},
  file = {/Users/john/Library/CloudStorage/OneDrive-UW/zotero_library/Schwock_Abadi_2021_Characterizing underwater noise during rain at the northeast Pacific.pdf}
}

@inproceedings{schwock2021e,
  title = {Statistical {{Properties}} of a {{Modified Welch Method That Uses Sample Percentiles}}},
  booktitle = {{{ICASSP}} 2021 - 2021 {{IEEE International Conference}} on {{Acoustics}}, {{Speech}} and {{Signal Processing}} ({{ICASSP}})},
  author = {Schwock, Felix and Abadi, Shima},
  year = {2021},
  month = jun,
  pages = {5165--5169},
  issn = {2379-190X},
  doi = {10.1109/ICASSP39728.2021.9415074},
  abstract = {We present and analyze an alternative, more robust approach to the Welch's overlapped segment averaging (WOSA) spectral estimator. Our method computes sample percentiles instead of averaging over multiple periodograms to estimate power spectral densities (PSDs). Bias and variance of the proposed estimator are derived for varying sample sizes and arbitrary percentiles. We have found excellent agreement between our expressions and data sampled from a white Gaussian noise process.},
  keywords = {Acoustics,Conferences,Estimation variance,Gaussian noise,Mathematical model,Signal processing,Spectral estimation,Speech processing,Welch method},
  file = {/Users/john/Zotero/storage/B88P3ML9/Schwock and Abadi - 2021 - Statistical Properties of a Modified Welch Method .pdf;/Users/john/Zotero/storage/UNZ2MF4L/9415074.html}
}

@article{schwock2021b,
  title = {Statistical Analysis and Modeling of Underwater Wind Noise at the Northeast Pacific Continental Margin},
  author = {Schwock, Felix and Abadi, Shima},
  year = {2021},
  month = dec,
  journal = {The Journal of the Acoustical Society of America},
  volume = {150},
  number = {6},
  pages = {4166--4177},
  publisher = {Acoustical Society of America},
  issn = {0001-4966},
  doi = {10.1121/10.0007463},
  urldate = {2022-04-04},
  abstract = {Approximately 11\,400\,h of acoustic recordings from two sites off the Oregon coast have been evaluated to characterize and model the frequency and wind dependence of wind noise in the northeast Pacific continental margin. Acoustic data are provided by two bottom-mounted broadband hydrophones (64\,kHz sampling frequency) deployed at depths of 81 and 581\,m at the continental shelf and slope, respectively. To describe the spectral level versus frequency relation, separate linear models for the 0.2--3\,kHz and 3--25\,kHz frequency range are fitted to the data. While spectral slopes for the 0.2--3\,kHz range generally decrease with increasing wind speed, slopes remain constant (shallow location) or increase with increasing wind speed (deep location) above 3\,kHz. The latter is in strong contrast to results from previous studies. The relation between spectral level and wind speed is described by a piecewise linear model where spectral levels are approximately constant below a critical wind speed  {$v$} c vc  and increase linearly with logarithmic wind speed above  {$v$} c vc . It is shown that the critical wind speed and the slopes of the piecewise linear model strongly depend on the acoustic frequency.},
  file = {/Users/john/Library/CloudStorage/OneDrive-UW/zotero_library/Schwock_Abadi_2021_Statistical analysis and modeling of underwater wind noise at the northeast.pdf}
}
