Older residents were reminded of Second World War air raids as modern sirens warning of a flood or terrorist attack were tested in Oxfordshire.
One of the portable sirens which were tested in Oxfordshire
The county is the first in the country to trial two portable sirens, which will alert communities of a natural disaster or a serious imminent threat.
The devices, which were tested on Wednesday, are stored in a metal box.
Oxfordshire County Council said the sirens are about keeping the public informed rather than causing a panic.
The alarms can be used with a public address system to advise people on what action they should take in the event of a major incident.
John Kelly, the county council's emergency planning officer, said the idea of using the German manufactured devices came after the severe floods last year.
He said: "We felt we need to warn and inform the public slightly better.
"This (the sirens) is a final warning that it is really serious, particularly in flooding."
If the trials prove to be successful they could be used throughout the country.