How do we identify which channel has been watched?

People meters (PMs) are being installed in panel member households. PMs use TV audio signal to collect signatures which represent a combination of binary codes rather than actual audio recording of watched channels.

Data that is collected and stored in people meters is being sent to TMI‘s data collection center, where audio signals of referenced channels are also being transformed into binary codes. By matching binary codes received from people meters and binary codes generated in collection center, our system identifies which channel was watched in the household and at what time. As a result of above-mentioned process, system can also recognize time-shifted viewing. 

TMI owns two independent data-collection centers: main and backup. TV channels are referenced by several broadcasting sources, which provides solid technological re-insurance.