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How to date a recording using background electrical noise

robertheaton.com

21–30 of 35 posts

Re: How to date a recording using background electrical noise

#21
post #3

A video on the same subject: https://youtu.be/e0elNU0iOMY I really enjoy Tom Scott. Everything he puts out is wonderfully concise.

Yes, Tom Scott is one talented YouTuber.

See, for example, his video on microwaving frozen hamsters back to life[0], in which he interviews the 101-year-old J. E. Lovelock, the scientist who did the work back in the fifties.

[0]https://www.youtube.com/watch?v=2tdiKTSdE9Y

Re: How to date a recording using background electrical noise

#23
post #15

Earlier quoted context omitted.

Have you tried any 3Blue1Brown videos? Highly recommend

Yes and I believe their videos are one the best things on the Internet right now as far as math education is concerned. Same goes for {Computer,Number}phile. The reason they're high quality learning material is because the explanations of the various concepts respect weaker math backgrounds, without being desperate to be as reductive as possible or have clickbaity titles , and sometimes with downright wrong claims, t…

Agreed on all points, and yeah. Veritasium was more alright a while back, but they've gone WAY off the deep end nowadays. Beyond merely "no longer interested in their content", I think they might be actively damaging at this point.

Re: How to date a recording using background electrical noise

#24

Right below the author's comment, "Regardless of a grid’s size, the current flowing through it oscillates in perfect synchrony, at exactly the same frequency, throughout the whole grid," he presents a map of Western Europe's regional groups. I notice that Finland, Sweden, Norway, and Iceland comprise the Nordic Regional Group. Iceland? There is a lot of water between Iceland and the other three nations in its group.…

The map for Europe is a map of organizational/bureaucratic boundaries within the ENTSO-E; the world map on that page correctly omits regions not connected to the big synchronized grids.

Alaska, similarly, is a set of two isolated grids, connected only by organizational ties: https://en.wikipedia.org/wiki/Alaska_Interconnection

Re: How to date a recording using background electrical noise

#25

Sounds like anyone wanting to do a "proper" fake job will now need to separate out any existing hum, then add a new continuous "hum track" based upon those publicly available ENV values. Probably wouldn't even be all that hard.

Well subtracting the hum requires knowing the hum at that time, right?

Re: How to date a recording using background electrical noise

#27
post #12

So yet another argument for proper, balanced audio recordings and working noise gates.

Wouldn't help. The electrical noise will still be present when the noise gate opens (because the thing we're recording is above the threshold), so they can extract the frequencies they need from parts of the recording when there's signal (e.g. the voice we're recording). And since the signals can come from what the microphone captures, it's irrelevant if the cables are balanced.

Re: How to date a recording using background electrical noise

#28

Sounds like anyone wanting to do a "proper" fake job will now need to separate out any existing hum, then add a new continuous "hum track" based upon those publicly available ENV values. Probably wouldn't even be all that hard.

Well subtracting the hum requires knowing the hum at that time, right?

Yes,*and* its harmonics, which would have to be replaced as well if they're detectably present. Swapping hums isn't trivial.

Re: How to date a recording using background electrical noise

#29

Earlier quoted context omitted.

Well subtracting the hum requires knowing the hum at that time, right?

Yes,*and* its harmonics, which would have to be replaced as well if they're detectably present. Swapping hums isn't trivial.

If the goal is just to obfuscate the hum, couldn’t you just scramble it instead of “subtracting”? Especially if you’re not trying to replace the hum

Re: How to date a recording using background electrical noise

#30
post #11
post #9

Curious if this can be used to discern AI-generated voice recordings vs authentic. A determined faker could always add their own noise, but this be a good first-pass detector.

A recent approach along these lines is to do acoustic modeling of the vocal tract that would have produced the speech. Unsurprisingly, AI voices do not correspond to realistic human vocal tracts, for now. https://www.usenix.org/conference/usenixsecurity22/presentat...

can google's cloud measure our vocal tract topology from the bluetooth and wifi signals on our phone? expect this flaw in AI voices to be self healing, retrained, and corrected soon.
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