Waimakariri Mayor David Ayers was to meet noise control officers today to plan how to track down a mysterious low-pitched hum that is being heard throughout the district.
Rangiora couple Ron and Liz Kautz have been inundated with calls from people reporting hearing a similar noise after they featured in a North Canterbury News article last week.
The Kautzes say the hum they have been hearing for more than a year affects their sleep and "feels like a pressure wave in our heads".
They have asked Waimakariri District Council to investigate, but noise control officers have been unable to shed any light on the cause.
Mr Kautz said at least 10 people had called with a "wide variety" of responses - from "get used to it or move" to people saying they were relieved to know "it's not just me".
People reported hearing the hum in Rangiora, Ashley, Sefton, Balcairn, Amberley, Kaiapoi Eyreton and Loburn. Several people said they'd been hearing the noise for three or four years.
"They're all starting to come out of the woodwork," Mr Kautz said. "It's really positive. All the people seem quite genuine."
Mr Kautz said Mr Ayers sent an email to say he would discuss the issue with council noise control officers today "to plan a way forward in all of this".