The Federal Government's analysis of noise produced by controversial delivery drones has vindicated community complaints that the aircraft are loud and obtrusive.
At 69 decibels from 15 metres away, the noise level is equivalent to a loud television, a busy office or a leaf blower.
And it exceeds the 45-decibel daytime noise standard for residential areas in Canberra, the site of the world-first service.
This week's publication of the measurement is the first milestone in a national review of drone noise, which will call for public submissions later this month.
The sound was measured from 15 metres away, to mimic the experience of a delivery recipient's neighbour.
Acoustic scientist at SLR Consulting, Matthew Bryce, said based on the measurement, drones produced a similar amount of noise to a loud television or radio.
"It might be equivalent to, say, your next door neighbour using a blower," he said.
"Because you're quite a bit away from it, and it's such a small source, it can be considered quite noticeable and loud."
Drones have a 'particular pitch', government says
Mr Bryce also noted drone noise had a distinct character.
"They have a rather unique, or rather distinguishable noise character, quite a high frequency noise," he said.
"Those types of noises tend to be more noticeable, and certainly discernible, and some people find them objectionable."
The Department of Infrastructure's website states it "acknowledges that the drone has a particular pitch that would be different to other sounds experienced within a suburban environment".
Earlier this year, the Federal Government realised it was responsible for regulating drone noise, and commenced a review.
It followed a community backlash about drone noise during the Canberra trial, which saw residents complain drones could be heard from inside well-insulated homes.
As the world's most advanced location for the rollout of drone deliveries, Australia is providing a regulatory model monitored by other nations — and interested companies, such as Amazon.
New propellers offer promise of quiet flight
Drone operator Wing has already developed a noise abatement propeller and promises more improvements.
Wing, which is part of the Google group of companies, declined to comment to the ABC.
Its operations in Canberra and a newly-announced service in Logan, Queensland, are limited to an average of 40 daytime flights per suburb per day.
A spokesperson from the Department of Infrastructure said an issues paper for the national drone review was due for release by the end of the month.
"Submissions from the public and industry will be welcome as part of the review process."
