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In this study, finite element modeling is used to investigate how these structures influence the transmission of water-borne sounds to the ears. The models are based on volumetric representations derived from computed tomography scans of a live bottlenose dolphin (Tursiops truncatus). The anatomical structures included in the model are iteratively modified and the predicted head-related transfer functions are used as a proxy for comparison. The results show that the MFBs, which support a lower sound speed than the surrounding tissues, significantly enhance the forward receiving directionality at echolocation frequencies through refraction in a manner similar to the melon in shaping the dolphins' highly directional transmission beams. Additionally, it is shown that in the frequencies encompassing dolphin communication signals, the air volumes help block the otherwise complex sound transmission through the bones. These findings highlight convergent evolutionary solutions in toothed whale anatomy to create strong directionality in both sound emission and reception governed by the same physical principles.<\/jats:p>","DOI":"10.1121\/10.0036904","type":"journal-article","created":{"date-parts":[[2025,7,8]],"date-time":"2025-07-08T08:38:24Z","timestamp":1751963904000},"page":"222-234","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":2,"title":["Head-related transfer function predictions reveal dominant sound propagation mechanisms to the dolphin ears"],"prefix":"10.1121","volume":"158","author":[{"given":"YeonJoon","family":"Cheong","sequence":"first","affiliation":[{"name":"Applied Physics Laboratory, University of Washington 1 , Seattle, Washington 98105,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Ruesch","sequence":"additional","affiliation":[{"name":"Neuroscience Institute, Carnegie Mellon University 2 , Pittsburgh, Pennsylvania 15213,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3511-6172","authenticated-orcid":false,"given":"Matt D.","family":"Schalles","sequence":"additional","affiliation":[{"name":"Neuroscience Institute, Carnegie Mellon University 2 , Pittsburgh, Pennsylvania 15213,","place":["USA"]},{"name":"Division of Social Science, New College, Florida 3 , Sarasota, Florida 34243,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jana M.","family":"Kainerstorfer","sequence":"additional","affiliation":[{"name":"Biomedical Engineering, Carnegie Mellon University 4 , Pittsburgh, Pennsylvania 15213,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5096-5914","authenticated-orcid":false,"given":"Barbara","family":"Shinn-Cunningham","sequence":"additional","affiliation":[{"name":"Neuroscience Institute, Carnegie Mellon University 2 , Pittsburgh, Pennsylvania 15213,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4112-2034","authenticated-orcid":false,"given":"Wu-Jung","family":"Lee","sequence":"additional","affiliation":[{"name":"Applied Physics Laboratory, University of Washington 1 , Seattle, Washington 98105,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"231","published-online":{"date-parts":[[2025,7,8]]},"reference":[{"key":"2025070808381774600_c1","doi-asserted-by":"publisher","first-page":"388","DOI":"10.1121\/10.0000557","article-title":"Directional hearing sensitivity for 2\u201330\u2009kHz sounds in the bottlenose dolphin (Tursiops truncatus)","volume":"147","year":"2020","journal-title":"J. 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