Interesting Article - GoFuckYourself.com

BIGTYMER · 01-06-2013, 03:10 PM

Quote:

To Pinpoint Audio Evidence, UK Police Record 7 Years Of Background Noise
The electrical hum in the background of a call can identify precisely when it happened.

Metropolitan police in London have been recording the hum of the nation's electrical grid for the last seven years, the BBC reports. And not just for fun: fluctuations in the sound enable audio forensic experts to pinpoint the time when any digital recording--of, say, a phone call--was made.

The hum varies subtly, a matter of millihertz, due to power demand and supply, so that there is a consistent signature associated with any point in time since the recording has begun. Simultaneously, any other recording that's made in the vicinity of a power line or appliance picks up the faint hum in the background.

By matching the hum in the background of a telephone recording with the master record of all electrical humming over the last seven years, the police can ascertain the exact time when the recording was made. This Electric Network Frequency analysis can verify the provenance and continuity of a recording as well, and has held up as crucial evidence in UK court.

Link: http://m.popsci.com/technology/artic...t-audio-crimes

Va2k · 01-06-2013, 03:13 PM

Damn that is interesting!!!!!!!

seeandsee · 01-06-2013, 03:21 PM

i dont have time to read it all, but is that noise cover-able for hole country or just some city or what?

BIGTYMER · 01-06-2013, 03:42 PM

Quote:

Originally Posted by seeandsee

i dont have time to read it all, but is that noise cover-able for hole country or just some city or what?

Just the city. But they might be using it in multiple cities.

01-06-2013, 03:13 PM	#2
Va2k I’m still alive barley. Industry Role: Join Date: Oct 2001 Location: Va Posts: 10,060	Damn that is interesting!!!!!!! __________________

01-06-2013, 03:21 PM	#3
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