{"id":225,"date":"2016-04-28T20:15:45","date_gmt":"2016-04-28T20:15:45","guid":{"rendered":"http:\/\/labs.la.utexas.edu\/gilden\/?page_id=225"},"modified":"2016-04-28T20:52:55","modified_gmt":"2016-04-28T20:52:55","slug":"measuring-the-coherence-threshold","status":"publish","type":"page","link":"https:\/\/labs.la.utexas.edu\/gilden\/measuring-the-coherence-threshold\/","title":{"rendered":"Measuring the Coherence Threshold"},"content":{"rendered":"

Measuring the Coherence Threshold<\/em><\/strong><\/p>\n

Metronome designers have done what most good engineers do when specifying systems for human use.\u00a0 They have built in a little slack.\u00a0 If the exit ramp states that 25 mph is a safe speed, you can probably do it at 35 mph without losing control.\u00a0 40 bpm is safe but it is a little conservative.\u00a0 The actual note spacing is a little wider than 1.5 seconds for music to lose its coherence.\u00a0 The following experiment illustrates how I measured the coherence threshold using a straightforward method of adjustment.<\/p>\n

The web is full of midi files that can be imported into a sequencer such as Cubase.\u00a0 My lab assistant picked out 24 songs that would be highly familiar to University of Texas undergraduates.\u00a0Dancing Queen, Sweet Dreams, <\/em>and Money for Nothing<\/em> gives an idea of the songs we used \u2013 familiar top 40 tunes.\u00a0 Sections of each song were imported into Cubase and the participants listened to them while they adjusted the tempo.\u00a0 Their instructions were to pick a tempo at which the song began to become difficult to recognize \u2013 where the notes started to separate into islands.\u00a0 If you have used Cubase, you will recall that the tempo can be controlled by the mouse.\u00a0 This is what the participants did.\u00a0 They just moved the mouse until the music stopped sounding like music to them.\u00a0 The experimenter then wrote down the tempo they selected.\u00a0 Each participant judged each of the 24 songs 4 times.\u00a0 Their averaged data is shown in the adjacent graph.<\/p>\n

\"coherence(3)\"<\/a><\/p>\n

On the x-axis I have plotted the average number of notes per beat.\u00a0 Most of the songs have a few eight notes and some have passages with sixteenths.\u00a0 From the graph you can see that the average top-40 pop song has about 1.5 notes per beat being largely comprised of quarter and eight notes.\u00a0 The y-axis is tempo and is the variable that the participants adjusted.\u00a0 Tempo here is measured as seconds per beat rather than as beats per minute.\u00a0 The principal finding from this experiment is that all of the songs scatter around a common line.\u00a0 The slope of this line is 1.9 seconds per note and it gives the overall spacing at which songs lose their musical coherence.\u00a0 For music made up of quarter notes this corresponds to a tempo of roughly 30 bpm.<\/p>\n

Previous: Melody is Emergent<\/a>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0Next: Activated Memory<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"

Measuring the Coherence Threshold Metronome designers have done what most good engineers do when specifying systems for human use.\u00a0 They have built in a little slack.\u00a0 If the exit ramp states that 25 mph is a safe speed, you can probably do it at 35 mph without losing control.\u00a0 40 bpm is safe but it […]<\/p>\n","protected":false},"author":107,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-225","page","type-page","status-publish","hentry","entry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"site-graphic":false},"uagb_author_info":{"display_name":"ecw255","author_link":"https:\/\/labs.la.utexas.edu\/gilden\/author\/ecw255\/"},"uagb_comment_info":0,"uagb_excerpt":"Measuring the Coherence Threshold Metronome designers have done what most good engineers do when specifying systems for human use.\u00a0 They have built in a little slack.\u00a0 If the exit ramp states that 25 mph is a safe speed, you can probably do it at 35 mph without losing control.\u00a0 40 bpm is safe but it…","_links":{"self":[{"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/pages\/225","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/users\/107"}],"replies":[{"embeddable":true,"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/comments?post=225"}],"version-history":[{"count":6,"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/pages\/225\/revisions"}],"predecessor-version":[{"id":277,"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/pages\/225\/revisions\/277"}],"wp:attachment":[{"href":"https:\/\/labs.la.utexas.edu\/gilden\/wp-json\/wp\/v2\/media?parent=225"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}