{"id":2889,"date":"2016-12-28T11:11:26","date_gmt":"2016-12-28T11:11:26","guid":{"rendered":"http:\/\/nayrb.org\/~blog\/?p=2889"},"modified":"2016-12-28T03:47:25","modified_gmt":"2016-12-28T03:47:25","slug":"the-limits-of-human-hearing","status":"publish","type":"post","link":"http:\/\/nayrb.org\/~blog\/2016\/12\/28\/the-limits-of-human-hearing\/","title":{"rendered":"The limits of Human Hearing I"},"content":{"rendered":"<p>Now that we&#8217;ve generated a .wav file from our sine wave, let&#8217;s take a look at some of the limitations of music as it&#8217;s written for the human ear[1].<\/p>\n<p>We&#8217;ll start with the low end of human perception.<\/p>\n<p>As you may recall, <a href=\"http:\/\/nayrb.org\/~blog\/2016\/12\/27\/if-you-wish-to-make-a-song-from-scratch-you-must-first-invent-the-universe\/\" target=\"_blank\">last time<\/a>, we made a 100Hz sine wave:<br \/>\n<!--[if lt IE 9]><script>document.createElement('audio');<\/script><![endif]-->\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-1\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_100Hz_works.wav?_=1\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_100Hz_works.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_100Hz_works.wav<\/a><\/audio><\/p>\n<p>This is near the bottom of what most humans can hear (and close to the bottom of what I can sing), but there&#8217;s still <a href=\"https:\/\/en.wikipedia.org\/wiki\/There's_Plenty_of_Room_at_the_Bottom\" target=\"_blank\">plenty of room<\/a> to explore.<\/p>\n<p>One octave down, we have 50Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-2\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_50Hz.wav?_=2\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_50Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_50Hz.wav<\/a><\/audio><\/p>\n<p>This is as low as I can comfortably hear (and sing!).  Below this, for various reasons, things get much quieter[2] and more difficult to produce.<\/p>\n<p>25Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-3\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_25Hz.wav?_=3\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_25Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_25Hz.wav<\/a><\/audio><br \/>\nAt normal volumes (halfway up on my laptop) sounds quite soft, but still audible.  At louder volumes, it sounds like something you might hear in the 8-bit audio of a game from the early &#8217;90s, perhaps in a dungeon to tell you something is oozing out of the wall.<\/p>\n<p>12.5Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-4\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_12-5Hz.wav?_=4\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_12-5Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_12-5Hz.wav<\/a><\/audio><br \/>\nTo me, this is inaudible at normal volumes.  At high volumes, it feels like what gargling would sound like in an 8-bit world.<\/p>\n<p>6.25Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-5\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_6-25Hz.wav?_=5\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_6-25Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_6-25Hz.wav<\/a><\/audio><br \/>\nAt normal volumes, still inaudible.  At high volumes, almost like water.<\/p>\n<p>3.125Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-6\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_3-125Hz.wav?_=6\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_3-125Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_3-125Hz.wav<\/a><\/audio><br \/>\nIf the previous one sounded almost like water, this is the real deal.  Still inaudible (as you would expect) at normal volumes.<\/p>\n<p>1.0675Hz:<br \/>\n<audio class=\"wp-audio-shortcode\" id=\"audio-2889-7\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/wav\" src=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_1-0675Hz.wav?_=7\" \/><a href=\"http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_1-0675Hz.wav\">http:\/\/nayrb.org\/~blog\/wp-content\/uploads\/2016\/12\/test_1-0675Hz.wav<\/a><\/audio><br \/>\nI totally did not expect to go this low in frequency.  This sounds perhaps even more like water at high volumes.  I wonder why all of these do.  Maybe it&#8217;s some other effect unrelated to the actual frequency of the sinewave, perhaps waves (and water) do actually make sounds at such low frequencies, or those low frequencies make secondary effects\/harmonics at high amplitudes.<\/p>\n<p>Next time, we&#8217;ll look at the high end of human hearing.  Stay tuned[3]!<\/p>\n<p>[1]I&#8217;m leaving out discussion of making music to be felt by other parts of the body, although that is probably a large part of why dance clubs are so popular.  We could also talk about different species, using devices, perhaps mediated human listening to music, but that is outside of scope.<\/p>\n<p>[2]I had assumed it had to do with the amount of energy being transmitted being non-linear with the frequency, but apparently it has more to do with human hearing.  &#8216;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Equal-loudness_contour\" target=\"_blank\">Equal-loudness contours<\/a>&#8216; will show you the way.<\/p>\n<p>[3]Hee.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Now that we&#8217;ve generated a .wav file from our sine wave, let&#8217;s take a look at some of the limitations of music as it&#8217;s written for the human ear[1]. We&#8217;ll start with the low end of human perception. As you may recall, last time, we made a 100Hz sine wave: This is near the bottom &hellip; <a href=\"http:\/\/nayrb.org\/~blog\/2016\/12\/28\/the-limits-of-human-hearing\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">The limits of Human Hearing I<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[38,24],"tags":[],"_links":{"self":[{"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/posts\/2889"}],"collection":[{"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/comments?post=2889"}],"version-history":[{"count":5,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/posts\/2889\/revisions"}],"predecessor-version":[{"id":2900,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/posts\/2889\/revisions\/2900"}],"wp:attachment":[{"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/media?parent=2889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/categories?post=2889"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/nayrb.org\/~blog\/wp-json\/wp\/v2\/tags?post=2889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}