Uncompressed, 1 hour of phone audio is only ~29MB (8KB/sec*3600s/h). Compressing it for storage can send that way down. Let's assume to 6MB. If every 300M Americans talked for an hour a day, that's only 2TB a day for call audio.
Edit: That's only one-way, so double. But compression can eliminate most of that, as there's usually only audio on one side of a call at a time. Anyways, even if I'm right within a factor of 10 or so, it doesn't really seem like a suspiciously high volume of disks.
(Disclaimer: I'm very drowsy just been woken up due to a datacenter coolant failure so maybe I miscalculated it.)
Wouldn't the information be more useful in text form? Transcripts would take far less space and would probably be necessary for any sort of useful search. They might even call the transcript "meta-data".
Exactly, just speech-to-text the whole thing and you're done. Bonus: it's a lot speedier to search through.
Since you don't have to justify yourself in court, you're never going to have to submit the actual audio to any judge as evidence, so why would you keep it?
Unless the NSA also has speech to text that is decades ahead of everyone else, AND works perfectly well in ~50 languages of interest - because of transcription quality.
Not necessarily - the speech to text just has to be good enough to flag likely use of interesting terms. Those calls could then be fully stored for later analysis by an investigation if it becomes necessary. The vast majority of calls would end up being stored as a text file, but this technique with today's technology would certainly be good enough to flag a reasonably high percentage of calls of interest for audio storage. That phone call from Jimmy to Sally Mae telling her he's going to be late home from work? It doesn't matter if NSA-Siri garbles the translation...
You're right and that makes far more sense. I apologize for this idiotic calculation. I should have known better because just capturing call signalling on one company's network, was taking 1TB compressed a day. To be fair I did add a disclaimer :\.
See my comment about two-way. It wouldn't matter much as it's rare that both parties are speaking at the same time.
It's also possible that the compression techniques for long-term storage are vastly superior to realtime codecs. The lowest realtime voice codecs are 300-600 bits per second (they sound like shit), which is 213x compression (so an hour would be under a a meg).
81TB a day. Again, this is assuming one hour of calls for 300 million people.
I did a quick search and found this snippet: "A telephia survey said that Americans average 13 talking hours a month – with the 18-24 age group averaging 22 hours."[1]
So that is under half an hour a day average. So, let's assume 300bps (lowest realtime voice codec I'm aware of), half hour a day, I'll stick to 300M people and we get:
Edit: That's only one-way, so double. But compression can eliminate most of that, as there's usually only audio on one side of a call at a time. Anyways, even if I'm right within a factor of 10 or so, it doesn't really seem like a suspiciously high volume of disks.
(Disclaimer: I'm very drowsy just been woken up due to a datacenter coolant failure so maybe I miscalculated it.)