42 Audio Illusions & Phenomena! - Part 1/5 of Psychoacoustics

Video Description

***!!! You must disable audio enhancement before listening !!!*** On windows "disable all enhancements" for all devices, on mac disable "sound enhancer", on mobile make sure you aren't using mono audio, and if you have a control panel for your headphones make sure to disable any and all similar stuff ("enhancements", "auto leveling", Dolby Atmos, etc)! Noise canceling headphones might also mess with these demonstrations! "Simulated surround sound" headphones, etc. -- all these things may affect the "truth" of what you're hearing. You also need to listen to the 720p version or better -- the lower-quality streams degrade the audio (including the stereo separation). This series presents a variety of fascinating psychoacoustic phenomena and illusions. We will cover 42 of them, with examples and explanations along the way. See if they work on you! Donation links: http://lacinato.com/donate | http://patreon.com/lacinato Series playlist: https://www.youtube.com/playlist?list=PL618khw0A-t51dsZ8DQK5fYkwrowtFYKn Errata: · the Tritone Paradox demo audio is incorrect: it is supposed to be a tritone apart, and was in my audio project, but a rendering glitch driving the automation of the synth I made caused it to be more like a step apart. The illusion is real, but my demo is bad. :-) There is a corrected version in Part 7: https://youtu.be/qdTloDvvy10?t=265 · re: binaural beats: some people can't hear them. There is apparently a difference between genders, and menstruation may also play a role in whether a person can hear this effect. If you can't hear them, you might try again another time. More info in "Auditory Beats in the Brain" by G. Oster -- PMID: 4727697 DOI: 10.1038/scientificamerican1073-94 There is also a common issue where on some systems the left and right channels are "polluting" each other. In the actual audio there is only a single tone in each ear at 2:20. If you take out an earbud (and you're sure you can't ear the earbud you took out through the air at all), you should definitely hear no beating at 2:20. You can test your system by taking one earbud out and playing from 2:12: when the audio plays one channel and then the other, you should hear total silence in the single earbud for one of those tones. If you hear even a little bit bleeding through, it means your system is not separating the channels properly (and in fact this may explain a lot of the cases where other illusions in this series don't work!) Try finding a playback system that isolates the left/right signals perfectly at 2:12, and then watch the videos again. I'd also appreciate reports under this comment about whether your system does or doesn't perfectly isolate the left/right channels on your headphones. · re: otoacoustic emissions: in the video I mention that OEs may result in tinnitus; I wanted to note that tinnitus has many (many) possible causes and having tinnitus does not necessarily mean that you have OEs. - combination tones: starting at 9:56 the synth used to generate those sine tones was slightly out of tune (user error). It shouldn't affect the demonstration much, if at all, but that's why there is a slight beating to the sound. Index to Part 1: 0:00 intro 0:55 binaural beats 3:09 pitch circularity 5:42 tritone paradox 7:23 tempo circularity 9:43 combination tones 10:38 missing fundamental 13:00 otoacoustic emission Tritone paradox: Deutsch, D. (1991). "The tritone paradox: An influence of language on music perception". Music Perception. 8 (4): 335–347. doi:10.2307/40285517. JSTOR 40285517 Risset beats created with (a slightly modifed version of) Dan Stowell's SuperCollider script: https://swiki.hfbk-hamburg.de/MusicTechnology/826 https://supercollider.github.io/ Check out these cool pitch circularity tracks: https://youtu.be/wiMzVdn4gDE https://youtu.be/dBYq9N-Lkzg Otoacoustic emissions image from: Dalhoff, E. et al "Distortion product otoacoustic emissions measured as vibration on the eardrum of human subjects." Proceedings of X the National Academy of Sciences 104.5 (2007): 1546-1551; https://doi.org/10.1073/pnas.0610185103 This video was made in Reaper and Blender, with final editing/compositing done in Davinci Resolve. Some custom software was written to generate various tones and such, and this was done in JSFX in Reaper.