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This study emphasizes the deep water soundscape of the Laccadive Sea by performing passive acoustic measurements over two distinct periods\u2014November 2020\u2013May 2021 and March 2022\u2013December 2022\u2014to reveal temporal variations and underlying patterns during the COVID-19 pandemic and post-pandemic periods. This research focuses on a comprehensive analysis of ambient noise spanning a frequency range from 20 to 2000\u2009Hz. Biophonic sources dominate within the 200\u20132000\u2009Hz range during the pandemic period. This study emphasizes the increased shipping noise levels at 63 and 125\u2009Hz frequencies during the post-pandemic period. The results indicate an increase in overall ambient noise post-pandemic periods, particularly within low-frequency bands associated with shipping. These findings suggest a temporary decrease in ambient noise in the acoustic environment of the Laccadive Sea during the pandemic, which was likely influenced by human activity restrictions.<\/jats:p>","DOI":"10.1121\/10.0039886","type":"journal-article","created":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T13:32:40Z","timestamp":1763559160000},"page":"3970-3978","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["Quantifying changes in the Laccadive Sea soundscape: A comparison of the COVID-19 pandemic and post-pandemic periods"],"prefix":"10.1121","volume":"158","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2443-5434","authenticated-orcid":false,"given":"R.","family":"Keerthivasan","sequence":"first","affiliation":[{"name":"National Institute of Ocean Technology , Chennai-600100,","place":["India"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. 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