This entry is part 3 of 9 in the series The Five(ish) Senses

Joe, Toren, and Kevin continue the Five(ish) Senses series this week with Hearing. We’ll cover how our bodies take in and process sound waves, the various causes of hearing loss, Hyperacusis, hearing in the animal kingdom, the Greater Wax Moth, Krakatoa, and noise pollution. Then it’s on to the history of hearing aids, news, and pop culture!

Music: “Sounds of Tindalos” by The Darkest of the Hillside Thickets





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18 Responses

  1. The bit with the ear trumpets made me think of one other use of them, air-raid warning. Before radar became common, there were a lot of different attempts to give a warning of incoming aircraft, and there were rigs that involved a pair of massive ear-horns (as in having horns with a ‘mouth’ a couple of feet across) on rotating stands that attempted to hear the coming aircraft.

    Another thing that came to mind was, during the discussion of the early electronic hearing aids, was an urban legend involving a ‘time traveler’ in an old Charlie Chaplin ‘behind the scenes’ film clip. A woman can be seen walking along holding something to her ear, and some jumped to the conclusion of that she was somehow using a cell phone. Those with some knowledge of the time pointed out that the device was about the right size for the time period for a hearing aid.

    Great show, and keep up the good work.

  2. I loved this one, as I am one of those that wear hearing aids. All though I am a little disappointed that in “pop culture” you did not mention the ultimate deaf person movie Mr. Hollands Opus. I thought surely that Toren, being a musician, would either enjoy the movie, or find the end at least interesting.

  3. My partner is 35 and can hear the young hertz level – she was teaching at a high school and called out kids that were always amazed that she could hear their text notifications.

  4. Did you guys see the recent article about tinnitus? Basically it causes people to be more irritable.

  5. You mentioned the F1 cars at full volume, they’re quieter now due to new design requirements and a reliance on Hybrid Electric engines rather than full on piston power.
    That being said, the difference is only about 10 decibels, down to 134 from 145.


    Still, it was enough of a difference for the city of Melbourne to complain that the cars weren’t loud ENOUGH during the Australian Grand Prix this year, and tried to sue the FIA because of it.


    Formula 1 is hilarious.

  6. One of the coolest things I’ve ever heard (well, it appealed to me) was from the RadioLab podcast talking about sound as “touch at a distance”. They did a whole episode looking at how sound and music and voice, etc, all contribute to touching people’s lives. Not very caustic, I know, but I thought it was a really wonderful idea.

    Also, Kevin, if you like bizarrely named parts of the body, I know the eye has some parts called the Zonules of Zinn. No idea what they are, but I bought a book with the title about them and other parts of the body and will get a bit more info for you on them if you like. I think the argument goes that lots of parts of the body were named back in the History when medicine was all Wild West and such, and so people named bits all sorts of crazy things. I heard about the book on another podcast called the Brain Science Podcast (awesome show, just like RadioLab (but neither come close to Caustic Soda, of course!)). 🙂

    1. The Zonules of Zinn sound like they should be a cabal gathered around a boiling cauldron…. I APPROVE!

      1. LOL!

        I found the book: “Beyond the Zonules of Zinn” by David Bainbridge, 2008.

        “Radiating out from the edge of each [eye] lens are hundreds of tiny fibers attaching the lens to a serrated muscular ring. When the muscles in this ring contract, they tug on the miniscule fibers, and it is this tug that flattens the lens and allows you to see into the distance. These fibers really are very small… Yet tiny as they are, these little strands have a name filled with portent. They are the zonules of Zinn.” (p4)

        So I guess they’re the little lines that make up your iris (or are, at least, nearby).

        Other parts of the brain he describes include the obex, the aqueduct of Sylvius, and the tract of Goll, which sounds like something out of D&D.

  7. Great episode. I’m an engineer that has occasionally done noise studies for environmental impact statements. Working with decibels is a pain in the neck, to give you an idea of how the math works, if you have one 70 dB speaker and add another right next to it and you want to know what the volume would be:

    70 db = 7 bells so the cumulative volume would be

    log (10^7 +10^7) = 7.3 bells or 73 decibels.


  8. So I was sitting here listening to this episode and there was Joe doing the hertz heraring test. I couldn’t hear the under-40 level (?15,000 Hz? whatever it was) but my dogs started barking. And every time Joe did the next hertz level, the dogs kept on barking.

    Does this mean that my dogs get more out of Caustic Soda than I do?