New Zealand's Humming

Need a grounding pitch?

Scientists investigating a strange humming sound in the New Zealand city of Auckland believe they have pinpointed the frequency.

The source of the noise, however, remains a mystery.

According to Dr Tom Moir, a computer engineer at Massey University's Institute of Information and Mathematical Sciences, the low level drone is almost certainly hitting the scales at a frequency of 56hz.

That however, has not brought the sleuths any closer to pinpointing the source of the hum which they have dubbed the Unidentified Acoustic Phenomena.

Dr Moir rules out geological factors. "It's more likely to be things like pipes under the ground - you know, gas pipes, sewerage pipes, factories in the distance."

It could also be a 'trick-or-treat' request.