The escape hatch with all personal data processing is "legitimate interest". Consent is a big part of it, but an industry with sufficiently deep legal pockets would likely go down the route of "legitimate interest" if cornered.

I'm not a legal professional. I just work next to this stuff.

That's not what legitimate interest is supposed to mean though.

Legitimate interest is about collection of data necessary to operate your service.

Listening to detect if someone in a user's surrounding is showing a match without license has nothing to do with the function of the application. There's no legitimate interest there.

I think a lot would depend on whether they do any kind of on-device processing to determine whether the audio is likely to be a football match or not. I think they could successfully argue that data processed on your phone and not shared with them is processed by you, and then they could argue that the data that is shared falls under legitimate interests and would be proportionate, and pass a balancing test.

IANALEither