{"id":207,"date":"2021-09-06T14:14:00","date_gmt":"2021-09-06T21:14:00","guid":{"rendered":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/?p=207"},"modified":"2022-03-04T12:59:53","modified_gmt":"2022-03-04T19:59:53","slug":"what-do-acousticians-do","status":"publish","type":"post","link":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/2021\/09\/06\/what-do-acousticians-do\/","title":{"rendered":"What do acousticians do?"},"content":{"rendered":"\n<p>(<em>This post was originally published September 24, 2021. <\/em><em>Posts have been manually reordered for more logical storytelling.<\/em> <em>To go to the next post in the sequence, click &#8220;Previous Post&#8221; at bottom.<\/em>)<\/p>\n\n\n\n<p class=\"has-drop-cap\">Think of a command center \u2014 a single person monitoring many screens all around them. This is what we acousticians call home while at sea. On the Gyre Expedition, we listen to sounds in the ocean in real time, detected by a long cable containing underwater microphones (known as <em>hydrophones<\/em>) towed behind the research vessel <em>Pacific Storm<\/em>. We use a variety of software tools to visualize these sounds, because our human sense of vision is much better than our sense of hearing (unlike the beaked whales and other marine mammals we study).<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"761\" src=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-1024x761.jpg\" alt=\"\" class=\"wp-image-217\" srcset=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-1024x761.jpg 1024w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-300x223.jpg 300w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-768x571.jpg 768w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-1536x1141.jpg 1536w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-2048x1522.jpg 2048w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Annamaria1-1568x1165.jpg 1568w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>Acoustician Annamaria DeAngelis (left) calls up to the bridge to give Captain Yogi Briggs instructions on where to steer the vessel. Acoustician Daniel Gillies (right) is viewing actual beaked whale calls depicted graphically on the television on the wall. The lines on the map will intersect where the whales are located.<\/figcaption><\/figure>\n\n\n\n<p>Sound is measured on a frequency scale, and our hearing has evolved to be sensitive to frequencies important to us. As we age (starting as early as 20 years old), our hearing deteriorates over time, especially for very high frequency sounds. Do you live in a rural area with very little background noise? Do you wear earbuds often? Are you a construction worker listening to the constant sounds of engines and machinery? Our individual experiences and interactions with sound in our daily lives make our hearing capabilities unique to each of us.<\/p>\n\n\n\n<figure class=\"wp-block-video\"><video height=\"512\" style=\"aspect-ratio: 1030 \/ 512;\" width=\"1030\" controls src=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Bairds_soundclip_unaltered.mp4\"><\/video><figcaption> This is a sound clip recorded from the Baird\u2019s beaked whale sighting earlier on our expedition. Watch the image scroll by as the sound plays. Each of these lines is a click from a Baird\u2019s beaked whale. Baird\u2019s use these clicks to look for prey items, and each click presents them with a &#8220;picture&#8221; of their environment, much like sonar or radar. Can you hear something when you see the green bar pass over vertical lines? Probably not. (Nor can most acousticians!)<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-video\"><video height=\"720\" style=\"aspect-ratio: 1280 \/ 720;\" width=\"1280\" controls src=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Bairds_soundclip_0.5x_amplified.mp4\"><\/video><figcaption> Here is the same sound clip, slowed so that the frequency is more suitable for human ears. Can you hear them now? (You may need to turn up your volume a bit.)<\/figcaption><\/figure>\n\n\n\n<p>Most marine mammals vocalize outside of the human hearing range. This is why we need so many displays \u2014 to <em>see<\/em> this &#8220;ultrasonic&#8221; sound. Each display provides specific information about these vocalizations, maps indicating the location of the sounds, and forms for recording additional data.<\/p>\n\n\n\n<p>Listening to beaked whales from our \u201ccommand center\u201d reminds me of playing whack-a-mole. Our primary display consists of little dots, each representing a click, which scroll by telling us about the time and location of the animal that produced them. Clicking on each dot produces three diagnostic plots that provide more information, as seen below. These dots flash by and are typically visible for about one minute as new clicks continue to stream in.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1714\" height=\"869\" src=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1.png\" alt=\"\" class=\"wp-image-222\" srcset=\"https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1.png 1714w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1-300x152.png 300w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1-1024x519.png 1024w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1-768x389.png 768w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1-1536x779.png 1536w, https:\/\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/4672\/files\/2021\/09\/Acoustics-Pamguard-1-1568x795.png 1568w\" sizes=\"auto, (max-width: 1714px) 100vw, 1714px\" \/><figcaption> Images produced by our acoustic software (Pamguard) while listening to beaked whales. The top display shows clicks produced through time (most recent on the left), with each color representing a different frequency. Clicking on any dot produces three additional plots below. Beaked whale clicks have a unique shape visible in the Wigner plot (with green background). The shape of the curve and placement of the peaks in the Click Spectrum (to the left of the Wigner plot) indicate the species of beaked whale producing the sounds.<\/figcaption><\/figure>\n\n\n\n<p>There is still much to learn about species-specific characteristics of beaked whale vocalizations. This expedition is providing us data to add to a growing library of knowledge, ultimately with a goal of identifying beaked whale species based solely on the sounds they make. The recent Baird\u2019s encounter was one such fortunate event where the whales dove within two to three football fields of us and stayed nearby, allowing us to capture thousands of clicks to study. A very rare treat!<\/p>\n\n\n\n<p class=\"has-text-align-right\"><em>~Annamaria DeAngelis<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>(This post was originally published September 24, 2021. Posts have been manually reordered for more logical storytelling. To go to the next post in the sequence, click &#8220;Previous Post&#8221; at bottom.) Think of a command center \u2014 a single person monitoring many screens all around them. This is what we acousticians call home while at [&hellip;]<\/p>\n","protected":false},"author":4200,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-207","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/posts\/207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/users\/4200"}],"replies":[{"embeddable":true,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/comments?post=207"}],"version-history":[{"count":12,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/posts\/207\/revisions"}],"predecessor-version":[{"id":315,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/posts\/207\/revisions\/315"}],"wp:attachment":[{"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/media?parent=207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/categories?post=207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/agsci-labs.oregonstate.edu\/gyrex\/wp-json\/wp\/v2\/tags?post=207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}