A Whangarei resident is concerned tsunami sirens in his area are not loud enough to get people out of bed and leave their homes.
Colin Lee of One Tree Point said the fact a lot of people in his area slept through the sirens after last week's earthquake in Kaikoura amazed him.
"With the building code now stipulating that all housing must have double glazing, it was almost impossible to hear the sirens, especially in the One Tree Point, Kowi Lake, La Point Estate and Marsden Cove area.
"People were confused whether the alarms were house alarms or unsure of what the alarm was. It seemed to a lot of people that the test siren and the actual siren were two totally different sounds and, even when the testing is done, it is hard to hear them."
Mr Lee said he felt there was a concern that needed to be addressed.
"If you can appreciate living close to the port and the refinery, we are hearing sirens on a regular basis, so it would make a lot of sense to have a lot louder system put in place so there is no confusion for the local residents.
"After hearing the sirens on the TV from the South Island and Wellington, these seem to be a lot louder and a totally different sound than what we hear up here," he said.
Northland Civil Defence Emergency Management group controller Tony Phipps said people should not just rely on tsunami sirens as there were multiple forms of alerts.
He said Monday morning's tsunami warning was the largest-scale evacuation undertaken in Northland and people responded well.
"If a neighbour phoned them or knocked on their door, or someone tooted their car horn as they drove away, that is also part of the way that communities look after themselves."
Mr Phipps said Northland has the largest network of tsunami sirens in the country, at 157 sirens or 35 per cent of the national total, according to a 2013 study.
He said the network was expanded every year and following on from Monday, there might be community support for adding even more tsunami sirens this year.
"We're also aware that a lot of Northlanders are now thinking about their preparedness for a tsunami and there are some easy things that people can do today, without needing to wait for the tsunami siren network to be expanded."
Hazard apps for smartphones downloaded for free and online maps to find out whether people lived or worked in a tsunami evacuation zone and their evacuation routes were other ways people could be alerted, Mr Phipps said.
The group was also looking into tsunami sirens people could purchase and install at their homes.