This isn’t news so much as validation. A new study is the latest evidence that overheard cell phone conversations are more distracting than regular overheard dialogue. The difference is that your brain tries to fill in the missing half of the conversation, thus making it difficult to focus on anything else. I’ve written about rude people before, and there have been several other studies saying basically the same thing. But you can never have too much ammunition when waging war against jerks.