Sound-activated advert touted as a world first; audience will “cheer” for favourite clip.

A sound-activated cinema advert for a Lynx shampoo will screen ahead of The Dark Knight Rises in five cinemas in London, Manchester, Liverpool and Scotland.

According to Lynx, the advert will “show men in different scenarios keeping up with a variety of girls”, after which the audience will be invited “to pick which girl they find the most demanding” and “cheer for the clip (and girl) they would like to see in full.”

An audio trigger will be linked to a server, which gauges the level of interaction and feeds the results back to the screen in real time.

The clip which receives the loudest response will then be played in full before the film. The advert will run for two weeks.