Technology
Multi-microphone audio recorder
Founder
Dr Jim Lovell
More information
Email: jim@astroacoustics.au
Web: astroacoustics.au
Aim
Make directional acoustic monitoring more accessible and effective.
Background
Bioacoustics is a non-invasive way of studying animals. But the technology has limitations. Most often, units have a single microphone, recording sound that is then analysed to identify which species are present. However, the direction to the sound cannot be identified so animal populations and movement cannot be determined. This can be overcome if multiple recorders are used but the deployment and analysis process is difficult, complicated and labour-intensive.
Scientists use other techniques but they are also problematic. For example thermal imaging doesn’t provide a complete solution, and capturing, tagging and radio-tracking species is expensive, time intensive and invasive.
But what if it were possible to identify and locate species with a single recorder?
Dr Jim Lovell is proving this proposition possible, applying radio astronomy techniques to bioacoustics. Jim is developing a directional acoustic monitoring unit with 8 microphones that will record the data necessary to establish species numbers by determining the direction to the sound. What’s more, if multiple 8-microphone units are deployed, there’s enough data to determine species’ territorial boundaries, habitat use and interactions.
How it’s being used at The Quoin
Development of this new 8-microphone recorder — from design through to a final product that anyone can use — is a multi-stage process in which The Quoin plays an important role.
The recorder is currently in the prototype stage, with units being manufactured at Definium Technologies for lab and field testing over the coming months. Meanwhile, traditional acoustic recorders have been deployed on the property to provide long-term baseline data on species currently present and how that changes as the property is managed and rehabilitated over time. This not only indicates what to expect from the new recorder, but will also provide a direct comparison between the two.
All data collected at The Quoin is being archived so that more species calls can be retrospectively identified as the AI models improve. Plus, the prototype system is equipped with wireless communication hardware. This, combined with the long-range wide-area (LoRaWAN) network already installed at The Quoin will allow remote control and monitoring, an important aspect of efficiently managing multiple recorders over a large area.
At the moment, we are focussing on searching for and monitoring bats and the endangered Australasian bittern (Botaurus poiciloptilus). Both have calls with distinguishing characteristics, making them readily identifiable using models already generated by AI algorithms in support of the state-wide citizen science program CallTrackers.
Broader applications
Less than 15% of Tasmania’s threatened species are monitored — this puts conservationists and policymakers at a disadvantage. If we don’t know which at-risk populations are declining most rapidly, we can’t effectively prioritise conservation efforts. Directional acoustic monitoring has the potential to transform the way government funding is allocated to species protection, and enable conservationists to work proactively rather than reactively.