Audience. That magic word. People who listen. Or in German, die zuschauer, people who watch. Like les spectateurs in French, where they are also just le public. In many languages, audience is basically ‘the public’. But perhaps not so naïve or unsuspecting any more...

The audience was again under the spotlight at this year’s Edinburgh Fringe Festival. The notorious show of the same name by Ontroerend Goed provoked some strong reactions. Others like White Rabbit, Red Rabbit pushed the boundaries more gently.

The first thing to say is that audience numbers held up. Much as it hurts to waste space reproducing press-release material… It seems 1,877,119 tickets were sold in 2011, up from 1,829,931 in 2010 (neither includes free, non-ticketed events). The number of shows also edged up to 2,542. If these are harder times, move over Mr Gradgrind.

The second thing to say is that alternative interaction is now traditional. Much as I liked Allotment or The Strange Undoing of Prudencia Hart, there have been site-specific shows before. Sailing On, staged in the ladies’ loo of the freemasons’ lodge, continues the tradition of performances in a zoo, container or swimming pool. Maybe if you choreograph me, you will feel better, in which Tania El Khoury invites men to direct her movements, both uses and subverts the format of headphone instructions. Dance Marathon could be linked to Silent Disco or Office Party. If you go back far enough, we’re all related…

Audience by Ontroerend Goed did seem to go one stage further. After some friendly reminders not to eat crisps, the company rifles through its audience. Total Theatre’s editor Dorothy Max Prior, in her online review, wrote that a young woman was ‘insulted, harangued and harassed in the most unpleasant way imaginable’. She described how: ‘The camera remains on her, in close-up, throughout. Her face is enormous onscreen, her lip is trembling, her eyes blinking away the tears. The actor says that he will only stop if she agrees to “spread her legs for the camera”.’If the aim was to test audience reactions, Matt Trueman describes some interesting countermoves on his blog, Carousel of Fantasies. One man pre-empted and dampened the moment by leaping up to rescue the damsel, he says. As for Trueman himself: ‘I had no qualms about taking £30 to start a chant: “Spread your legs. Spread your legs.”’

A key question was whether the girl was a plant, for all or some of the run. This reminded me of the furore surrounding the Brendon Burns show So I suppose this is offensive now, which won the not-the-Perrier main comedy prize four years ago. Unlike the open discussion, gossip, rumour surrounding Audience, the critics maintained a blanket silence in 2007. No one spilled the beans that the Asian lady being so vehemently abused by the Australian comedian for our amusement was actually a plant.

This year, White Rabbit, Red Rabbit questioned the traditional audience dynamic more subtly. Nassim Soleimanpour’s script was given a cold reading by a different actor each day. It required volunteers to become animals on stage, take notes or photos, while playing with time, distance and location. This was heightened by the writer’s own position – potentially inaccessible or dangerous – in Iran.

Another contrast is with Frisky and Mannish. Their parting shot in Pop Centre Plus – ‘we’ve been Frisky and Mannish and you’ve been superfluous’ – was only partly tongue in cheek. They do work the audience: we are divided into five types or ‘career paths’ (Razorlight, Britney, Justin Bieber, Elvis and Echo, the first being those with wonderful hair but little else…) and later a ‘man band’ is manufactured with style and alacrity (told to touch each other inappropriately for the camera…). But in other ways, F&M’s talent did dwarf the audience. You could enjoy watching from behind the wall.

Cards on the table: I had the advantage of not seeing Audience. An earlier Ontroerend Goed show, Internal, did catch a personal nerve. I was left feeling my fantasies were inadequate, boring, overly contained, among other things. It has been argued that the company should distinguish between a professional audience of theatre-makers and the genuine public. I’m not so sure this is the only point. Their provocation is still within the boundaries of theatre, while on stage (as to what they do offstage, well, that would be for the Belgian authorities to judge). The moral repulsion is both valid and worn.

Perhaps the debate about interactivity is linked to technology. Sites like Facebook, for which people photograph events before experiencing them, make participation inescapable. However, theatre also has a great recalcitrance with technology. To the extent that it is live, in the moment, paring down the mediation to bare the soul, it’s the enemy of superficial and virtual interactivity. This can also make it self-indulgent, nostalgic or disengaged.

Generally, my encounters at Edinburgh with fellow audience members have been underwhelming. Obstacle courses, elbows, the odd friendly word, shared programme, free whisky… but no peck on the cheek, no children in or out of wedlock. And of course, while some people were safely watching the Fringe, others got a bit too interactive with stray water bottles during looting in London. Now that’s what I call spur-of-the-moment participation…