A low flying helicopter over the Ipswich waterfront has been causing a stir among passersby this afternoon.

A member of the public contacted this paper to say the helicopter was “causing a lot of stares and confused faces”.

Organisers of the Spill Festival confirmed the chopper was theirs preparing for tomorrow’s world premier of Clarion Call – one of the many attractions during the 11 day event.

Billed as a “large scale outdoor sonic artwork,” Clarion Call will ring out across the waterfront at sunset each evening.

On the Spill website the artwork is described as: “The voices of women and girls call to the setting sun in daily incantations, broadcast with audio technology employed for emergency and control, repurposed as a mechanism for public ritual.”

Featured vocalists include Elizabeth Fraser from Cocteau Twins and Beth Gibbons from Portishead.

Organisers of the festival said the helicopter had been checking the sound levels ahead of tomorrow’s first sunset peformance,

The helicopter could also be seen from nearby Christchurch Park.

A dog walker said she had been “amazed” to hear the voices drifting across the park as the sky turned pink.

“It was a really weird experience – quite incredible,” she added.

Visit Spill Festival for more information.