Learning to Listen to the Wild

Wildlife Arts Science Sound Nature Research

International Dawn Chorus Day

We want to engage the public in the value and beauty of our local soundscapes! To raise peoples’ awareness we are organising the Newhaven Soundcamp event this weekend of 5-6th May 2018, as part of the International Dawn Chorus Day – a worldwide celebration of the dawn chorus which reminds us of the close relationship between human wellbeing and that of all other living species.

For this weekend, we will be installing a small radio transmitter on the cliff tops of Newhaven, linking The Living Coast biosphere to a network of open microphones around the world which are located at sites of ecological and sonic interest. You can join us virtually now at this overnight event by listening in to the live soundscapes generated by the 2018 spring avian orchestra as the dawn chorus sweeps around the world this weekend!West Beach Newhaven - Soundcamp

The Newhaven Soundcamp is one of many events internationally contributing to a 24 hour broadcast of the dawn chorus - curated by arts group Soundcamp - as a network of listening points at sunrise on International Dawn Chorus Day. Listen in to the curated stream by following the links on the Soundcamp website.

Newhaven Soundcamp is organised by the Experimental Music Technologies (Emute) lab at the University of Sussex, in association with The Living Coast, supported by Sussex Humanities Lab and Sussex Sustainability Research Programme at the University of Sussex and generously hosted by Newhaven Community Garden.

You can listen in to microphones around the world at any time at various sites including:

Enjoy the different soundscapes!

Soundscape research

Measuring the impact of people on the environment continues to present a major challenge for our sustainable management of landscapes. Traditionally, survey methods often involve carrying out ecological assessments that attempt to identify the wildlife present and relate them in a particular environment and relate this to its ecological health. However, counting different species represents a big challenge requiring taxonomic expertise and lots of survey effort and time.

Seeking alternative approaches to this challenge, scientists have been exploring the potential of sound in recent years to provide a rapid measure of the species present – as a proxy for ‘biodiversity’ - and even a more holistic measure of ‘ecological health’. The analysis of sounds generated by environments is a relatively new field known as ‘Soundscape Ecology’. It aims to study the patterns, causes and consequences of sounds made by humans (‘anthrophony’), other biological organisms (‘biophony’) and geophysical processes (‘geophony’). By learning to listen to soundscapes in the right way it is becoming possible to use sound as a monitoring tool of the richness of life – ‘biodiversity’.

At the University of Sussex at Falmer we are based in the heart of The Living Coast, and over the last few years we have carried out acoustic surveys both in temperate habitats in and around our Unesco World Biosphere Region and in tropical habitats of the Andes of NW Ecuador. We seek to better understand the relationships between the sounds present in each habitat and the species that live in them there.

As it would take a lifetime to listen to all the recordings individually, we need to use computers to ‘listen’ for us. Our approach does not attempt to identify individual species calls – this is particularly challenging in tropical environments where the sounds of many species remain unidentified and the calls of birds, frogs and insects are often densely interwoven. Instead, the soundscape approach listens to the chorus as a whole, to all the sounds that can be heard across a particular landscape. The technical challenge for us is to find ways to describe the digital audio recordings of these environments mathematically, so that the process can be carried out by a computer, but in ways which are meaningful for their ecology. These mathematical summaries are known as ‘audio features’ or ‘acoustic indices’. Our research explores how these acoustic indices relate to the number of species present, or other ecologically relevant information.

So how does it work? Programmable, weather proof audio recorders are positioned in trees and set to record through the day and night for weeks at a time. We make hundreds of thousands of short recordings across all sorts of different habitats and at different times of day, and then analyse the digital audio files using these mathematical algorithms to generate a set of numbers of the patterns of acoustic energy in each recording.

To test whether these numbers might be useful as a proxy for biodiversity, we compare the results from traditional biodiversity survey methods – lists of the number and abundance of different species at each site. In the UK this is mostly bird species, so we ask bird experts (‘ornithologists’) to listen to the same files and estimate the number of species and numbers of individuals of each species in each file. In tropical Ecuador however, the analysis task is much more complex with its wealth of frogs and insects making lots of noise!

We compare the mathematical summaries with the ornithologists’ estimates to see how well the acoustic indices predict species numbers and abundances. If the traditional biodiversity measures and new computer indices show the same patterns of variation across time and habitat types, then it suggests they are measuring the same thing. Our work has shown strong correlations between the two – the results are really promising!

This technology does not replace the expertise of field scientists, but would allow us to carry out rapid surveys of biodiversity across inaccessible wild areas and across larger areas or longer timescales that are not possible using current methods. This new approach could provide a really valuable tool to assess the impacts of climate change or industrial development, or positive improvements happening as a result of conservation efforts, such as those in our very own Biosphere here.

Dr Mika Peck & Dr Alice Eldridge
University of Sussex

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