There's a Persistent Hum in Windsor, Ontario, and No One Knows Why

Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by Waterluvian on Tuesday February 20, 2018 @04:53PM (#16424572)

Sigh. I've coded too much this week. My brain just immediately went to: comment out half the city at a time and binary search the source. Guess you can't really do that.

I wonder if the hum persists during a power outage.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by vlasev on Tuesday February 20, 2018 @05:05PM (#16424674)

Replace "comment out" by "turn off the electricity for" and maybe we can binary search it.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by asaph on Tuesday February 20, 2018 @06:09PM (#16425164)

Your implicit assumption is that the hum is caused by something electrical; i.e. not a diesel engine or some natural cause.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by Waterluvian on Tuesday February 20, 2018 @06:16PM (#16425214)

But that's exactly the point. It would rule out a ton of stuff.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by Untit1ed on Tuesday February 20, 2018 @06:11PM (#16425177)

Then we can turn off the electricity for the whole town and see if it stops! :D

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by incompatible on Tuesday February 20, 2018 @06:57PM (#16425503)

"The University of Windsor report said the hum’s likely source was blast furnace operations on Zug Island" ... which is over the border in the United States.

Cutting off the power to that island would be a good thing to try, but apparently the US is uncooperative.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by manojlds on Wednesday February 21, 2018 @07:01AM (#16428791)

But might have to turn off electricity for days if generators are used.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by fredsmith42 on Tuesday February 20, 2018 @06:28PM (#16425306)

I don't think that Windsor was compiled with the debug flags turned on.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by thinkingemote on Tuesday February 20, 2018 @05:02PM (#16424655)

I've heard the hum in a city in the UK quite frequently. I hear it more on monday bank holiday mornings, oddly. So a weekday but less people at work.

I actually think it's the sound of traffic.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by koolba on Tuesday February 20, 2018 @05:20PM (#16424790)

A few samples of amplitude should be able to triangulate it no?

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by rocqua on Tuesday February 20, 2018 @07:12PM (#16425616)

I'd guess amplitude is massively affected by microphone sensitivity. This is not easy to measure and might depend on the direction.

Consider:

* The amount of walls between a mic and the outside.

* The absorbance/reflection of nearby materials, including their shape (flat surface will reflect sounds amplifying certain directions).

* The clutter between the source and receiver. Sound carries over water, not over cities or forests.

* Similarly, elevation of the receiver. Higher means less effect of clutter, and obviously, a hill in between will be an issue.

* Wind direction. Wind will blow the sound away.

It might still work with enough measurements with the same microphone, but that is not a given. A decent backup plan would be measuring the phase difference. This is still frustrated by wind, but doesn't depend on the senstivity of the microphones. It does require synchronization of the recordings, which might also be difficult.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by mindcrime on Tuesday February 20, 2018 @09:30PM (#16426384)

It does require synchronization of the recordings, which might also be difficult.

Could you record with a multiple "microphone connected to a Raspberry Pi" setup, with the time synchronized using something like the NIST time signal[1] using an RTL-SDR, or a cellular signal, or GPS, or maybe using NTP?

[1]: https://www.nist.gov/pml/time-and-frequency-division/nist-ra...

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by rocqua on Wednesday February 21, 2018 @06:20AM (#16428643)

Yes, that seems like the best approach. At 20Hz waves, ntp would probably be good enough. The real issue I can see is to get that time-data into the sound data. Maybe you could time-stamp the beginning of a recording, and start a new recording every minute (to compensate clock drift). That might work, biggest issue I see is potential variable latency between 'starting a recording' and the actual first recording happening.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by bufferoverflow on Tuesday February 20, 2018 @06:13PM (#16425195)

Just install the debugging microphones all over, collect the data, find the source (if it's real).

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by sneak on Tuesday February 20, 2018 @06:57PM (#16425504)

Why install anything? Fly a drone around to take 5s recordings at points on a grid.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by Cerium on Tuesday February 20, 2018 @07:48PM (#16425810)

Since cities support parallel execution you must have an array to capture coherent debug information.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by monk_e_boy on Tuesday February 20, 2018 @09:02PM (#16426234)

Wouldn't the sound of the drone be louder than the hum?

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by tntniceman on Tuesday February 20, 2018 @09:46PM (#16426434)

My assumption is that he would touch down first.

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Re:There's a Persistent Hum in Windsor, Ontario, and No One ... by demircancelebi on Tuesday February 20, 2018 @05:07PM (#16424685)

This actually sounds like a good idea.

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