To answer this question, let's bring to mind a typical conference experience: The brief interactive plenary presentation is nearing its climax, a focused audience of conference delegates has keenly taken in the handful of highly-engaging visual materials and is waiting with baited breath to hear the expert speaker's conclusion. When the invitation to ask questions comes, a dozen hands shoot up urgently and implore the emcee to hear theirs first.
All of that's complete fantasy, of course. Wouldn't it be nice if all conference presentations followed this pattern.
Instead what usually happens is this: The 40-minute monotonous lecture is winding down, the delegates in the conference hall shift in their seats restlessly when they hear the presenter say "So, in conclusion…".
Those who weren't already doing emails, WhatsApping or checking out their Facebook feed look up with relief. It was only supposed to be a 20-minute presentation, but with the presenter reading from his 57 text-filled slides there was no chance from the outset that this deadline would be met.
When the speaker opens the floor for the Q&A the audience is just relieved the sales pitch is over, and hopes no one asks any questions so s/he will finally get off the stage.
You don't need to present at TED in order to engage with authentic (!) humour and stories, to cut down the number of slides and replace text with video, charts and graphics, to omit the sales pitch, to use your voice for best effect, to keep it short. Make every presentation a TED talk.
In many conferences, I have found Asian delegates to be just as keen to ask questions during Q&A than Western ones. I have concluded that the problem with a dearth of questions doesn't lie with them.
The sum total of my years of experience as a conference anchor is this: if you want to know why Asian audiences don't ask questions, look no further than the presentation style of the presenters.