{"video_id":"WZLQoP6CM0k","title":"Decibels as Fast As Possible","channel":"Techquickie","show":"Techquickie","published_at":"2015-05-07T14:58:16Z","duration_s":320,"segments":[{"start_s":0.199,"end_s":5.64,"text":"we hear about decibel all the time when","speaker":null,"is_sponsor":0},{"start_s":3.679,"end_s":10.96,"text":"shopping for I don't know a Bluetooth speaker a wireless antenna or whatever","speaker":null,"is_sponsor":0},{"start_s":7.919,"end_s":13.04,"text":"else but many people I talk to are","speaker":null,"is_sponsor":0},{"start_s":10.96,"end_s":18.4,"text":"shocked to hear that when one thing is rated at twice as many decb as something","speaker":null,"is_sponsor":0},{"start_s":15.32,"end_s":21.439,"text":"else that does not mean it's twice as","speaker":null,"is_sponsor":0},{"start_s":18.4,"end_s":23.4,"text":"strong or twice as loud let's start at","speaker":null,"is_sponsor":0},{"start_s":21.439,"end_s":27.76,"text":"the beginning shall we the base unit in this case is actually the Bell named in","speaker":null,"is_sponsor":0},{"start_s":25.68,"end_s":32.279,"text":"honor of Alexander grambell who achieved Fame and Fortune most notably for filing","speaker":null,"is_sponsor":0},{"start_s":30.0,"end_s":35.559,"text":"a patent for the work of Antonio miuchi the true inventor of the telephone","speaker":null,"is_sponsor":0},{"start_s":33.719,"end_s":39.719,"text":"anyway that's a whole other discussion call me we'll talk about it sometime the","speaker":null,"is_sponsor":0},{"start_s":37.32,"end_s":46.12,"text":"point is one Bell represents a difference in a relative power of 10","speaker":null,"is_sponsor":0},{"start_s":42.8,"end_s":48.84,"text":"with a decibel being on10th of a bell so","speaker":null,"is_sponsor":0},{"start_s":46.12,"end_s":52.879,"text":"if one value is 10 DB higher than another it is an order of magnitude","speaker":null,"is_sponsor":0},{"start_s":50.8,"end_s":56.84,"text":"greater whereas a 20 dcel difference would be two orders of magnitude greater","speaker":null,"is_sponsor":0},{"start_s":54.879,"end_s":61.359,"text":"and so on and so forth well hold on a second lus if it's a unit of relative","speaker":null,"is_sponsor":0},{"start_s":59.16,"end_s":67.0,"text":"rather than AB absolute measure then how can we possibly say something like this","speaker":null,"is_sponsor":0},{"start_s":63.64,"end_s":70.2,"text":"is a 3 D antenna or this fan is rated at","speaker":null,"is_sponsor":0},{"start_s":67.0,"end_s":74.2,"text":"21 DBS you see that a next to the","speaker":null,"is_sponsor":0},{"start_s":70.2,"end_s":76.799,"text":"decibal symbol for that fan that is how","speaker":null,"is_sponsor":0},{"start_s":74.2,"end_s":81.52,"text":"it's all about context decibel have been adapted for many different uses so they","speaker":null,"is_sponsor":0},{"start_s":78.759,"end_s":86.4,"text":"can be expressed more easily by defining standard reference points or a base","speaker":null,"is_sponsor":0},{"start_s":84.28,"end_s":90.6,"text":"value in the case of an antenna's gain reputable companies will rate them in","speaker":null,"is_sponsor":0},{"start_s":87.92,"end_s":95.0,"text":"dbd or relative to a dipole while companies who want to show inflated","speaker":null,"is_sponsor":0},{"start_s":91.92,"end_s":97.119,"text":"numbers will rate in DBI relative to an","speaker":null,"is_sponsor":0},{"start_s":95.0,"end_s":101.2,"text":"imaginary antenna that radiates in all directions and then in the case of noise","speaker":null,"is_sponsor":0},{"start_s":99.28,"end_s":106.32,"text":"the main focus of this video we use sound pressure level a measurement in","speaker":null,"is_sponsor":0},{"start_s":103.479,"end_s":111.6,"text":"decb above a base value approximately equal to the threshold of human hearing","speaker":null,"is_sponsor":0},{"start_s":109.799,"end_s":115.479,"text":"okay cool Linus uh now I know what a deciel is but logarithmic units are a","speaker":null,"is_sponsor":0},{"start_s":113.88,"end_s":120.799,"text":"little hard to compare in your head when you're shopping for a cooling fan or air","speaker":null,"is_sponsor":0},{"start_s":118.52,"end_s":124.479,"text":"conditioner or something so onebody told me that I can just kind of go well a 3","speaker":null,"is_sponsor":0},{"start_s":122.52,"end_s":130.52,"text":"dbel gain is an effective doubling of sound well I heard from someone else","speaker":null,"is_sponsor":0},{"start_s":126.36,"end_s":133.2,"text":"that it's 6 DB which is right ha this is","speaker":null,"is_sponsor":0},{"start_s":130.52,"end_s":139.04,"text":"where things get really fun three DCB equates approximately to a doubling of","speaker":null,"is_sponsor":0},{"start_s":136.0,"end_s":141.08,"text":"the power ratio but when we want an","speaker":null,"is_sponsor":0},{"start_s":139.04,"end_s":145.16,"text":"amplitude ratio let's say to express relative voltage or a field quantity","speaker":null,"is_sponsor":0},{"start_s":143.239,"end_s":150.44,"text":"like sound pressure level we need to square the amplitude which means that a","speaker":null,"is_sponsor":0},{"start_s":147.36,"end_s":152.8,"text":"difference of 6 DB will equate to double","speaker":null,"is_sponsor":0},{"start_s":150.44,"end_s":157.879,"text":"the voltage or double the sound pressure level if you measure it but that doesn't","speaker":null,"is_sponsor":0},{"start_s":155.08,"end_s":162.44,"text":"mean to your ears a vacuum cleaner rated at 6 DB lower than another will actually","speaker":null,"is_sponsor":0},{"start_s":160.599,"end_s":168.04,"text":"sound half as loud as the next leading brand or whatever your ears don't hear","speaker":null,"is_sponsor":0},{"start_s":165.159,"end_s":172.0,"text":"increases in sound pressure in a linear fashion in fact depending on the","speaker":null,"is_sponsor":0},{"start_s":170.2,"end_s":177.159,"text":"frequency of the noise the general rule of thumb is that it takes somewhere","speaker":null,"is_sponsor":0},{"start_s":174.0,"end_s":180.239,"text":"between a 6 to 10 D increase in sound","speaker":null,"is_sponsor":0},{"start_s":177.159,"end_s":183.56,"text":"pressure to achieve a perceived double","speaker":null,"is_sponsor":0},{"start_s":180.239,"end_s":185.36,"text":"of loudness all right lonus I get it now","speaker":null,"is_sponsor":0},{"start_s":183.56,"end_s":189.44,"text":"but why do we need a unit of measurement that appears to have been designed to","speaker":null,"is_sponsor":0},{"start_s":187.28,"end_s":194.44,"text":"confuse people and make comparisons difficult fair question there is the bit","speaker":null,"is_sponsor":0},{"start_s":192.28,"end_s":198.959,"text":"about how human perception of sound and also light actually is more closely","speaker":null,"is_sponsor":0},{"start_s":196.799,"end_s":203.519,"text":"related to the logarithm of intensity rather than the intensity itself but the","speaker":null,"is_sponsor":0},{"start_s":201.239,"end_s":208.0,"text":"main reason is that it allows the use of much smaller numbers in cases where we","speaker":null,"is_sponsor":0},{"start_s":205.84,"end_s":213.76,"text":"need to compare values that can differ by many orders of magnitude instead of","speaker":null,"is_sponsor":0},{"start_s":210.28,"end_s":215.959,"text":"saying these speakers go 10 billion","speaker":null,"is_sponsor":0},{"start_s":213.76,"end_s":221.4,"text":"times louder than your weak human hearing threshold we just say it's 100","speaker":null,"is_sponsor":0},{"start_s":218.92,"end_s":225.76,"text":"DB SPL but if you're sitting there worried about how you're ever going to","speaker":null,"is_sponsor":0},{"start_s":223.28,"end_s":230.12,"text":"remember all of this fear not Wikipedia has a handy dandy chart that you can","speaker":null,"is_sponsor":0},{"start_s":227.959,"end_s":234.84,"text":"reference next time you see a loudness rating in decb so that you have some","speaker":null,"is_sponsor":0},{"start_s":232.4,"end_s":239.319,"text":"context for interpreting the otherwise truthfully pretty confusing numbers","speaker":null,"is_sponsor":0},{"start_s":237.56,"end_s":243.84,"text":"speaking of confusing today's episode sponsor linda.com an amazing way to","speaker":null,"is_sponsor":0},{"start_s":241.959,"end_s":247.76,"text":"increase your understanding of a variety of topics without unneeded confusion","speaker":null,"is_sponsor":0},{"start_s":246.159,"end_s":252.319,"text":"they offer thousands of courses with more added every week all pop by","speaker":null,"is_sponsor":0},{"start_s":249.599,"end_s":256.56,"text":"industry experts linda.com also offers a variety of awesome services to their","speaker":null,"is_sponsor":0},{"start_s":253.92,"end_s":260.959,"text":"members like their playlist Center where they have more than 100 if I could","speaker":null,"is_sponsor":0},{"start_s":259.639,"end_s":265.28,"text":"express that on my fingers I would mixtapes which are carefully tailored to","speaker":null,"is_sponsor":0},{"start_s":263.4,"end_s":269.16,"text":"certain learning objectives so for example if you want to get your start in","speaker":null,"is_sponsor":0},{"start_s":267.56,"end_s":274.759,"text":"app development or website design you can head over to to their playlist Center and select from a variety of","speaker":null,"is_sponsor":0},{"start_s":272.12,"end_s":278.6,"text":"mixtapes focusing on the many key areas of web and app design about which you","speaker":null,"is_sponsor":0},{"start_s":276.8,"end_s":282.479,"text":"may want to expand your knowledge linda.com memberships start at only $25","speaker":null,"is_sponsor":0},{"start_s":280.96,"end_s":287.24,"text":"per month but they're offering a special onewe free trial to Techquickie viewers","speaker":null,"is_sponsor":0},{"start_s":285.16,"end_s":289.919,"text":"just head over to linda.com tequ to start your trial today thanks for","speaker":null,"is_sponsor":0},{"start_s":288.919,"end_s":293.6,"text":"watching guys like the video if you liked it dislike it if you disliked it leave a comment letting me know if you","speaker":null,"is_sponsor":0},{"start_s":292.24,"end_s":298.039,"text":"have any suggestions for future fast as posses or if you have something to say","speaker":null,"is_sponsor":0},{"start_s":295.44,"end_s":302.8,"text":"that's more complicated than this thanks again for watching and as always don't","speaker":null,"is_sponsor":0},{"start_s":299.8,"end_s":305.4,"text":"forget to subscribe and share please","speaker":null,"is_sponsor":0},{"start_s":302.8,"end_s":311.96,"text":"share when you share I get a lot more subscribers and then my ego is like and","speaker":null,"is_sponsor":0},{"start_s":309.08,"end_s":319.6,"text":"then I get huge like this and I have no neck like","speaker":null,"is_sponsor":0},{"start_s":314.68,"end_s":319.6,"text":"this would you die without a neck","speaker":null,"is_sponsor":0}],"full_text":"we hear about decibel all the time when shopping for I don't know a Bluetooth speaker a wireless antenna or whatever else but many people I talk to are shocked to hear that when one thing is rated at twice as many decb as something else that does not mean it's twice as strong or twice as loud let's start at the beginning shall we the base unit in this case is actually the Bell named in honor of Alexander grambell who achieved Fame and Fortune most notably for filing a patent for the work of Antonio miuchi the true inventor of the telephone anyway that's a whole other discussion call me we'll talk about it sometime the point is one Bell represents a difference in a relative power of 10 with a decibel being on10th of a bell so if one value is 10 DB higher than another it is an order of magnitude greater whereas a 20 dcel difference would be two orders of magnitude greater and so on and so forth well hold on a second lus if it's a unit of relative rather than AB absolute measure then how can we possibly say something like this is a 3 D antenna or this fan is rated at 21 DBS you see that a next to the decibal symbol for that fan that is how it's all about context decibel have been adapted for many different uses so they can be expressed more easily by defining standard reference points or a base value in the case of an antenna's gain reputable companies will rate them in dbd or relative to a dipole while companies who want to show inflated numbers will rate in DBI relative to an imaginary antenna that radiates in all directions and then in the case of noise the main focus of this video we use sound pressure level a measurement in decb above a base value approximately equal to the threshold of human hearing okay cool Linus uh now I know what a deciel is but logarithmic units are a little hard to compare in your head when you're shopping for a cooling fan or air conditioner or something so onebody told me that I can just kind of go well a 3 dbel gain is an effective doubling of sound well I heard from someone else that it's 6 DB which is right ha this is where things get really fun three DCB equates approximately to a doubling of the power ratio but when we want an amplitude ratio let's say to express relative voltage or a field quantity like sound pressure level we need to square the amplitude which means that a difference of 6 DB will equate to double the voltage or double the sound pressure level if you measure it but that doesn't mean to your ears a vacuum cleaner rated at 6 DB lower than another will actually sound half as loud as the next leading brand or whatever your ears don't hear increases in sound pressure in a linear fashion in fact depending on the frequency of the noise the general rule of thumb is that it takes somewhere between a 6 to 10 D increase in sound pressure to achieve a perceived double of loudness all right lonus I get it now but why do we need a unit of measurement that appears to have been designed to confuse people and make comparisons difficult fair question there is the bit about how human perception of sound and also light actually is more closely related to the logarithm of intensity rather than the intensity itself but the main reason is that it allows the use of much smaller numbers in cases where we need to compare values that can differ by many orders of magnitude instead of saying these speakers go 10 billion times louder than your weak human hearing threshold we just say it's 100 DB SPL but if you're sitting there worried about how you're ever going to remember all of this fear not Wikipedia has a handy dandy chart that you can reference next time you see a loudness rating in decb so that you have some context for interpreting the otherwise truthfully pretty confusing numbers speaking of confusing today's episode sponsor linda.com an amazing way to increase your understanding of a variety of topics without unneeded confusion they offer thousands of courses with more added every week all pop by industry experts linda.com also offers a variety of awesome services to their members like their playlist Center where they have more than 100 if I could express that on my fingers I would mixtapes which are carefully tailored to certain learning objectives so for example if you want to get your start in app development or website design you can head over to to their playlist Center and select from a variety of mixtapes focusing on the many key areas of web and app design about which you may want to expand your knowledge linda.com memberships start at only $25 per month but they're offering a special onewe free trial to Techquickie viewers just head over to linda.com tequ to start your trial today thanks for watching guys like the video if you liked it dislike it if you disliked it leave a comment letting me know if you have any suggestions for future fast as posses or if you have something to say that's more complicated than this thanks again for watching and as always don't forget to subscribe and share please share when you share I get a lot more subscribers and then my ego is like and then I get huge like this and I have no neck like this would you die without a neck"}