system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do radio stations track the listener count?
gpt
Radio is measured in a few different ways, and to be in full disclosure, there is much debate on the accuracy of any of them as the margin of error was pretty high, and people lie in journals and surveys about radio fairly regularly.

1. Journals - literally a sample of people are given journals they write what they listened to each day and turn it in after a couple months.

2. "People meters"/"audio listening device thing"  Its a small microphone you wear or is in a certain place which listens and records what is playing, and the data is then sent to the ratings service.  This is becoming much more common now.

3. Surveys. Just plain simple radio surveys.