Dear Colleagues, My co-authors and I are excited to announce the following publication: Helble TA, Guazzo RA, Martin CR, Durbach IN, Alongi GC, Martin SW, Boyle JK, Henderson EE (2020). Lombard effect: Minke whale boing call source levels vary with natural variations in ocean noise. J. Acoust. Soc. Am. 142 (2): 698-712. DOI: https://doi.org/10.1121/10.0000596 Abstract: Minke whales were acoustically detected, localized, and tracked on the U.S. Navy’s Pacific Missile Range Facility from 2012 to 2017. Animal source levels (SLs) were estimated by adding transmission loss estimates to measured received levels of 42,159 individual minke whale boings. Minke whales off Hawaii exhibited the Lombard effect in that they increased their boing call intensity in increased background noise. Minke whales also decreased the variance of the boing call SL in higher background noise levels. Although the whales partially compensated for increasing background noise, they were unable or unwilling to increase their SLs by the same amount as the background noise. As oceans become louder, this reduction in communication space could negatively impact the health of minke whale populations. The findings in this study also have important implications for acoustic animal density studies, which may use SL to estimate probability of detection. Please email me (regina.guazzo@spawar.navy.mil) or Tyler Helble ( tyler.helble@navy.mil) if you have any questions about this work. All my best, Regina Regina A. Guazzo, PhD Environmental Readiness Branch Naval Information Warfare Center Pacific (c) 908.507.1421