THE VIDEO SHELF · audio forensics
The hidden background noise that can catch criminals
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.
Why HN readers recommended it
The go-to short, accessible explainer for mains hum forensics, linked whenever recording authenticity or timestamps come up.
This is a summary from the source dataset, not an endorsement by Hacker News or the video creator.
Video & recommendation details
- Creator / channel
- Tom Scott
- Topic
- audio forensics
- Format
- explainer
- Level
- general
- HN recommenders in dataset
- 3
- HN mentions in dataset
- 8
- Recommendation years in dataset
- 2022–2025
These counts and years describe the included Hacker News records; they are not YouTube views or the video’s publication date.
From the original HN conversations
Excerpts from the recorded comments. Follow each source for the full comment and surrounding discussion.
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. [VIDEO]
AnotherGoodName on Hacker News · 2022-08
In Extracting Audio from Visual InformationIf 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] [VIDEO]
subpar on Hacker News · 2023-02
In How to date a recording using background electrical noiseA video on the same subject: [VIDEO] I really enjoy Tom Scott. Everything he puts out is wonderfully concise.
Groxx on Hacker News · 2023-02
In How to date a recording using background electrical noise
Summaries, classifications and recommendation records are from the HackerTube source dataset. Read about this library and its limitations.