The hidden background noise that can catch criminals on HackerTube: recommended by 3 Hacker News commenters across 2 separate months, 2022–2025.
explainer · evergreen
Tom Scott explains Electrical Network Frequency analysis, where hum from the power grid in a recording is matched against grid logs to date and place it. He talks to a researcher and sets them a challenge.
The go-to short, accessible explainer for mains hum forensics, linked whenever recording authenticity or timestamps come up.
“less detailed but pretty accessible video [1] explaining how mains hum forensics work”
8 Hacker News comments link this video. Each one links back to its thread.
If this is interesting to you or your kids, here's a less detailed but pretty accessible video [1] explaining how mains hum forensics work, complete with British accent. [1] ▶ this video
in “How to date a recording using background electrical noise” · View on HN
A video on the same subject: ▶ this video I really enjoy Tom Scott. Everything he puts out is wonderfully concise.
in “How to date a recording using background electrical noise” · View on HN
If you haven't already seen tom Scott's video on background noise giving the location of a recording due to power line frequencies being subtly different I recommend it. ▶ this video
in “Extracting Audio from Visual Information” · View on HN
Reminds me of the 'mains hum' technique that was used to identify videos. Can also be done with light. ▶ this video [link]
in “Hiding secret codes in light protects against fake videos” · View on HN
Probably not practical but there was an interesting video by Tom Scott where investigators used the electrical hum background noise to determine when something was recorded. Maybe there is a way to audio record something to prove location. ▶ this video
in “Ask HN: Are there strategies for content creators to prove their location?” · View on HN
I'm writing a open-source library ( [link] ) and a webapp ( [link] ) that detects the Utility Grid noise emitted by electrical devices (A/C, motors, appliances ...) from Video/Audio recording. It then tries to date the recording by matching it to historical data. The signal processing part is getting decent. I'm still trying to collect more reference signals in RU, UK, China and Japan. Tom Scott made a video about the idea: ▶ this video
in “Ask HN: Tell us about your project that's not done yet but you want feedback on” · View on HN
According to a Tom Scott's video[1], you can use background noise emitted by electricity to prove that a recording has been taken at a certain time and place. [1]: ▶ this video
in “Wearable device that records your voice for legal defense” · View on HN
There are companies that already provide this kind of service so it might be interesting for you to combine efforts: ▶ this video
in “Launch HN: Reality Defender (YC W22) – Deepfake Detection Platform” · View on HN