Scarcely had John begun speaking when he was again booed by the audience.
This sentence sounds strange to me, it sounds like John had been booed before and now he was booed again, and during the "booing process", he started his speaking.
That doesn't make sense since it is much more reasonable he first started the talk, and then been booed.
What exactly is this sentence mean? John is somehow disliked by audience and whenever he occurred, the audience booed even he didn't start talking?
(BTW: please let me know if I made any strange usage or grammar incorrect when writing this question)