Semi Loud

The word for cicadas in Japanese is semi.  They have been chirping or is it singing lately. I will put up a picture of the bug behind a spoiler so some people won’t get creeped out. For others who just want to hear the semi symphony here is a video.

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26 thoughts on “Semi Loud”

  1. While we lived in what was always called a “leafy suburb” of Philadelphia, the cicadas were deafening in August.  There was the scratchy white noise you recorded, yes, but there was kinda a Doppler effect: it rose, both in pitch and volume, to an earsplittibg screech, tapered off, rose again.  That’s because in the suburbs, trees are much closer to the houses than they are here in the country.

    There are some species that emerge every year, but 2020 is the year for the 17- year locusts to emerge (in the US; dk if it’s the same globally)  So the awful cacophony of their mating calls is worse this year.

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  2. Hypatia:
    While we lived in what was always called a “leafy suburb” of Philadelphia, the cicadas were deafening in August.  There was the scratchy white noise you recorded, yes, but there was kinda a Doppler effect: it rose, both in pitch and volume, to an earsplittibg screech, tapered off, rose again.  That’s because in the suburbs, trees are much closer to the houses than they are here in the country.

    There are some species that emerge every year, but 2020 is the year for the 17- year locusts to emerge (in the US; dk if it’s the same globally)  So the awful cacophony of their mating calls is worse this year.

    I think it is louder in the city because there are so few trees. The bugs per tree are more. But I may be wrong.

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  3. It is striking how close the sound of massed cicadas is to white noise (sound with equal power at all frequencies).  I did a fast Fourier transform analysis of the audio from the video clip and got:

    FFT spectral analysis of cicada sound

    This spectrum is “tilted” toward frequencies higher than around 2 kHz, but is remarkably flat, with no dominant frequency.  (The spectrum of pure white noise would be completely flat.)  Here is the audio track from the video inter-cut with pure white noise adjusted to be around the same volume.  The track alternates cicadas—white—cicadas—white.

    [audio wav="https://www.ratburger.org/wp-content/uploads/2020/08/cic_wht.wav"][/audio]

    (Audio engineering joke I first heard from Donald Knuth: “What do you get when you mix rap with white noise?”  “Grey noise.”)

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  4. 10 Cents:
    The word for cicadas in Japanese is semi.  They have been chirping or is it singing lately. I will put up a picture of the bug behind a spoiler so some people won’t get creeped out. For others who just want to hear the semi symphony here is a video.

    Cicadas




    These bugs are about 2 to 3 inches long. Children like to catch them and put them in small plastic cages.

     

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    I know the noise of their singing can drive one mad after a while, but I’ve always liked cicadas as insects.

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  5. Bryan G. Stephens:
    They are in force here now. Our joke is they are saying ‘It’s Hot. It’s Hot”

    I think they, like other insects change speed with temp. Our just to it in Imperial

    I grew up in the Northwest. We never had cicadas. I had no idea insects could be this loud.

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  6. 10 Cents:

    Bryan G. Stephens:
    They are in force here now. Our joke is they are saying ‘It’s Hot. It’s Hot”

    I think they, like other insects change speed with temp. Our just to it in Imperial

    I grew up in the Northwest. We never had cicadas. I had no idea insects could be this loud.

    The swamp is pretty noisy.  The noisiest part of the day is at sunset in August, when the afternoon cicadas are still in full riot and the evening katydids start up.  Between the two of them, they even drown out all the frogs, which are making plenty of racket on their own.  And cutting through all that noise is the bleat of the Fowler’s Toads.

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  7. Bryan G. Stephens:
    They are in force here now. Our joke is they are saying ‘It’s Hot. It’s Hot”

    I think they, like other insects change speed with temp. Our just to it in Imperial

    I had to raise my voice with my wife last night (hot!) in order to be heard over the roar.  Intermittent in the cooler mornings, like right now.

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  8. Phil Turmel:

    Bryan G. Stephens:
    They are in force here now. Our joke is they are saying ‘It’s Hot. It’s Hot”

    I think they, like other insects change speed with temp. Our just to it in Imperial

    I had to raise my voice with my wife last night (hot!) in order to be heard over the roar.  Intermittent in the cooler mornings, like right now.

    What?! You get to speak, Phil. 🙂

    Has anyone measured the decibels on these critters? In the name of science get out the testing equipment.

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  9. 10 Cents:
    Has anyone measured the decibels on these critters?

    From Wikipedia:

    Although only males produce the cicadas’ distinctive sounds, both sexes have membranous structures called tympana by which they detect sounds, the equivalent of having ears. Males disable their own tympana while calling, thereby preventing damage to their hearing; a necessity partly because some cicadas produce sounds up to 120 dB (SPL) which is among the loudest of all insect-produced sounds. The song is loud enough to cause permanent hearing loss in humans should the cicada be at “close range”.

    For example, a chain saw operating at a distance of one metre has a sound pressure level of 110 dB.  The human threshold of discomfort is 120 dB and the threshold of pain is 130 dB.  A jet engine 50 metres away is 140 dB.

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  10. John Walker:

    10 Cents:
    Has anyone measured the decibels on these critters?

    From Wikipedia:

    Although only males produce the cicadas’ distinctive sounds, both sexes have membranous structures called tympana by which they detect sounds, the equivalent of having ears. Males disable their own tympana while calling, thereby preventing damage to their hearing; a necessity partly because some cicadas produce sounds up to 120 dB (SPL) which is among the loudest of all insect-produced sounds. The song is loud enough to cause permanent hearing loss in humans should the cicada be at “close range”.

    For example, a chain saw operating at a distance of one metre has a sound pressure level of 110 dB.  The human threshold of discomfort is 120 dB and the threshold of pain is 130 dB.  A jet engine 50 metres away is 140 dB.

    Wow!! I had no idea they would be that loud.

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  11. 10 Cents:

    Phil Turmel:

    Bryan G. Stephens:
    They are in force here now. Our joke is they are saying ‘It’s Hot. It’s Hot”

    I think they, like other insects change speed with temp. Our just to it in Imperial

    I had to raise my voice with my wife last night (hot!) in order to be heard over the roar.  Intermittent in the cooler mornings, like right now.

    What?! You get to speak, Phil. 🙂

    Has anyone measured the decibels on these critters? In the name of science get out the testing equipment.

    I have seen Environmental Impact Statements that were deceptive for this very reason.  The threshhold for mitigation on account of noise is based on the difference between anticipated levels of noise compared to the already existing background noise.   If you see that the background noise levels were determined in August or September, you can figure they wanted the highest possible background noise levels in order to make the project appear that it won’t add very much to the ambient noise.

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  12. MJBubba:
    I have seen Environmental Impact Statements that were deceptive for this very reason.

    There is also a lot of gaming due to sound propagation effects in measurement of sound pressure levels.  When it’s overcast, you tend to get sound reflected back from the cloud layer (or maybe it’s due to refraction due to temperature/density profile), but in any case you measure higher SPL at a distance than in a clear sky.  In Huntsville, when NASA would test rocket engines, they would only test on clear days because when it was cloudy they rattled and broke a lot more windows of their neighbours, which didn’t help with “community relations”.  I notice this in the sound from the rifle range across the route cantonale from my house: when it’s cloudless, it’s quieter, and the sound has a different character.

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  13. Up north I don’t remember ever having “plagues” of bugs. Cicadas come and go here but not other “plagues”.  In Florida while visiting my brother I came during love bug season. They were everywhere. The male and female seemed to have a suicide pack with car grills.

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