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I think it's an app specifically installed for the purpose. I just asked him what it was called, he said it was an Arbitron(now owned by Nielson) device. I goog
by sathackr 10y ago
I think it's an app specifically installed for the purpose. I just asked him what it was called, he said it was an Arbitron(now owned by Nielson) device. I googled Arbitron device and found this: https://en.m.wikipedia.org/wiki/Portable_People_Meter https://en.m.wikipedia.org/wiki/Portable_People_Meter
- maxerickson 10y agoNote that it doesn't use ultrasound, it embeds information in the normal audio in a way that humans are not likely to perceive (psychoacoustic masking).