The sound of a wetland after an inundation of water can be booming, with the arrival of frogs and birds quickly able to bring a quiet swamp to life.
It's a symphony that ecologists from Charles Sturt University and The Australian National University want everyone to be able to hear no matter where they're located.
In collaboration with the Commonwealth Environmental Water Office, thousands of minutes of audio from Nap Nap Swamp in NSW's Riverina have been recorded as part of a project named The Sound of Water.
The swamp, in Nari-Nari country, covers more than 2,000 square kilometres of wetlands near the confluence of the Lachlan and Murrumbidgee rivers.
Charles Sturt University associate professor Skye Wassens said remote weather-proof recording devices were used to collect five minutes of audio once an hour.
Environmental water is water that's allocated and managed to improve or maintain river and wetland systems.
"We get to hear woodland birds ... the wind and the rain as that wetland is dry and then we hear the water coming in and the frogs start to call."
Dr Wassens said she wanted to give people the opportunity to step into the wetland just by putting on a pair of headphones.
"These are places that aren't easy to get to and we wanted to share with everyone what these places are like, how noisy and vibrant they are when they're receiving water.
Sustaining populations in dry years
The swamp is located on private property on Nap Nap Station, whose manager, Hamish Cullenward, said they had worked closely with environmental water holders over the years.
"Through those dry years some of the critical wetlands were still getting water which was able to sustain the populations," he said, referring in particular to the endangered southern bell frog.
"When the water gets over the country, it's just about deafening between all the species of frogs and mainly migratory bird species.
Soundscapes show changes over time
Dubbo-based artist Kim Goldsmith has long known the intricacies of the sound of water, having spent years creating soundscapes of river catchments.
"I think the important thing about monitoring sound in our waterways is doing it constantly over time; that's when you can start to track the change," Ms Goldsmith said.
One of her recent projects was on the Lachlan River where she sampled sound from the top of the catchment, around Wyangala Dam, to the bottom at the Cumbung Swamp.
Ms Goldsmith said her microphones could pick up the sound of water bugs skirting across the top of water, or even fish grunting and carp moving across the bottom of a river bed.
"There are various sounds like that that we just can't hear; only those specialist microphones allow people a glimpse of that underwater world."
