The film is by no means silent the whole way through. To encourage audiences to focus on what they’re hearing, Shen combines 30-second-long static camera shots of scenes and their sounds – a tree in a field, a petrol station at night, a motorway – with interviews with people involved in the consideration of sound and silence all over the world, whether academics, monks or audiologists. It features Greg Hindy, a Yale graduate from New Hampshire, who took a vow of silence and walked across the United States for a year in an attempt to get away from the distractions of noise “embedded in electronics and entertainment”. It takes us inside the anechoic chamber at Orfield Laboratories in Minnesota, one of the quietest places on Earth, where the Guinness World Records team recorded a background noise level of –9.4 decibels.

The result is a film that is both calming and jarring to watch. In one particularly effective sequence, Shen films hundreds of workers in the City of London’s Lloyd’s Building, standing still to observe the Remembrance Day two-minute silence. The absence of noise and movement makes the scene look almost unreal, as if we’re watching a photograph instead of a video. Then the bell tolls to mark the end of the silence and the picture is instantly broken, all the sound we’re used to living with flooding back in.