Regarding amateur radio "broadcasts"... You may want to search for "GB2RS News", which as stated on the RSGB website is "the RSGB’s weekly radio broadcast news service relayed by our team of newsreaders to listeners across the UK and beyond every Sunday." The RSGB is the amateur Radio Society of Great Britain. It is not a broadcast which covers the country, but which is relayed by different amateurs for their local area. For America, see https://www.arrl.org/arrl-audi...

I suspect that one part of why hearing half a conversation is more annoying has to do with the intermittent nature of half a conversation. Whenever someone starts talking near me, particularly if they are using a loud voice, I listen for a moment to see if they are talking to me. If they are in a conversation where I an hear both parts it's easier to ignore as it's easy to tell that they are not addressing me. With the stop/start pattern of half a conversation, I think most people are subconsciously triggered to pay attention to see if someone wants to talk to them, every time the local speaker makes a remark.