{"id":235114,"date":"2026-04-13T23:35:38","date_gmt":"2026-04-14T04:35:38","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2026\/04\/ghost-tunnels-guide-sound-waves-in-one-direction-while-staying-invisible-to-others"},"modified":"2026-04-13T23:35:38","modified_gmt":"2026-04-14T04:35:38","slug":"ghost-tunnels-guide-sound-waves-in-one-direction-while-staying-invisible-to-others","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2026\/04\/ghost-tunnels-guide-sound-waves-in-one-direction-while-staying-invisible-to-others","title":{"rendered":"\u2018Ghost tunnels\u2019 guide sound waves in one direction while staying invisible to others"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/ghost-tunnels-guide-sound-waves-in-one-direction-while-staying-invisible-to-others2.jpg\"><\/a><\/p>\n<p>Acoustic metamaterials are a fast-evolving family of materials which manipulate sound waves in ever more advanced ways. Now, a team led by Changqing Xu at Nanjing Normal University in China has engineered an acoustic metamaterial, a \u201cghost tunnel\u201d: a structure which acts as a near-perfect waveguide for sound entering through its ends, while being essentially invisible to waves incident on its sides. The results, published in <a href=\"https:\/\/journals.aps.org\/prl\/abstract\/10.1103\/9y6g-42nm\" target=\"_blank\"><i>Physical Review Letters<\/i><\/a>, could open new avenues for manipulating sound waves in complex signal environments.<\/p>\n<p>Acoustic waveguides work by confining sound within a channel, using boundaries that reflect waves back inward to keep them on track. While this can be achieved with a structure as simple as a hollow pipe, the problem is that those same reflective boundaries inevitably interact with any sound waves approaching from outside the channel.<\/p>\n<p>Rather than passing through undisturbed, external waves scatter off the rigid walls: a significant drawback in technologies where multiple signal channels must coexist in close proximity without interfering with one another.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Acoustic metamaterials are a fast-evolving family of materials which manipulate sound waves in ever more advanced ways. Now, a team led by Changqing Xu at Nanjing Normal University in China has engineered an acoustic metamaterial, a \u201cghost tunnel\u201d: a structure which acts as a near-perfect waveguide for sound entering through its ends, while being essentially [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1635],"tags":[],"class_list":["post-235114","post","type-post","status-publish","format-standard","hentry","category-materials"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/235114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=235114"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/235114\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=235114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=235114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=235114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}