In order to capture full audio data, we will be using the Raspberry Pi Zero W boards to send data over WiFi, and we have now installed a new WiFi Access Point to receive the data. The Access Point is located on the South West corner of the University Main Library, as indicated by the blue arrow on this map:
The photo below shows a view of the library from the Meadows, followed by a close-up of the newly installed Access Point (a small grey box).
We are looking forward to testing the reception range of the new device.
An earlier post described my initial steps in building an audio monitoring device, and over the last couple of weeks, I have worked on putting the electronics inside an enclosure that is both waterproof and will not be too obtrusive when installed in a tree. We refer to it as the “bird-box”. The box is made largely of 3mm plywood, with some thicker wood framing. It’s been stained and varnished to weatherproof it. The design enables easy separate access to change the battery without dislodging the Raspberry Pi Zero W processor and the Ultramic. On the inside, we use hermetically sealed plastic lunch boxes to hold the sensitive electronics, with sealed punch-throughs for the various connecting cables. It’s cheap and very effective.
Our next step was to carry out some field-testing of the device. We decided to do this in the private garden of a University of Edinburgh property, close enough to the Meadows to capture representative samples of sounds in the environment. I installed a temporary WiFi access point in the building to pick up the data from the prototype device in the garden, which is collected on a laptop also sited within the building.
Here’s a small sample of what we recorded over the three days of wind, snow, rain and freezing temperatures. The unit performed well in these challenging conditions, including the 30,000 mAh power bank.
This audio sample is indicative of what kinds of things we can detect in the urban environment: an emergency siren in the background, a stonemason working on a nearby building, and a snatch of bird song. The spectrogram below illustrates the different frequency ranges at which the sounds occur, from 0kHz up to 20kHz.
The bottom pink line is ambient sound.
The faint wavey pink line above that is the siren.
The strong pink fence-like pattern above that is the sound of the stonemason tapping away.
Finally, the little pink burst (between 3kHz and 5kHz) just before the last two taps from the stonemason is the clearly-audible bird song.
Listen again whilst looking at the image and you can observe how the sounds interact with each other.
We are excited to see that the recording device, the WiFi router and the computer all seem to be working together well.
Pursuing our goal of collaborating with Edinburgh Living Landscapes and other partners to explore how soundscape data can support community engagement, education and citizen science and increase the value created by urban greenspace, we invited stakeholders and interested parties to an initial CitySounds Co-Design workshop on 9th January 2018.
It was a great event, full of ideas and enthusiasm. Here, we briefly mention the main topics of discussion.
Exploring and understanding the data that will be captured
The six audio monitoring devices will each record 10-second samples in rotation, focusing on biodiversity in the Meadows. The devices will operate 24/7.
We are hoping that these will pick up birds, bats (which cannot be heard by the human ear), rain, traffic noise, etc. It will be interesting to see how many anthropogenetic sounds occur in the ultrasonic range.
We should be able to detect bird sounds within a 50–100m range and bats within a 30m range. (Interesting fact: Bats are loud! Their signals are typically over 100 decibels)
We are in the process of installing a WiFi access point on the 6th floor of the University Main Library, facing the Meadows.
Data will be directly transferred via WiFi to a server—so no data will be kept on the devices themselves.
It was pointed out that it will be important to make it as easy as possible for small biodiversity organisations to access the collected audio data, since often these have little or no resources for dealing with technical intricacies.
Community engagement actions in the project: who are we targeting and what do we want to achieve?
We are planning to organise at least three community engagement events during the course of the project:
First data literacy workshop (open to stakeholders)
Second data literacy workshop (open to interested groups and the public)
A final sonic art exhibition open to the public.
We spent the last section of the workshop discussing various ideas for these events.
The two data literacy workshops
These workshops will be an opportunity to communicate with the public about acoustic data and to engage their interest in data, IoT and urban greenspaces. We discussed:
What are we trying to achieve in the workshops?
What issues should the workshops address?
How can these apply in general to biodiversity monitoring?
How can they apply to the green network across the city that Edinburgh Living Landscapes is creating?
What is the target audience for the workshops? People already involved in biodiversity activities?
Measuring impact of biodiversity initiatives in the city
How can Edinburgh Living Landscape, FOMBL, the CEC Biodiversity team, and other interested partners use acoustic data to create evidence and evaluate the impact of their work? We are hoping to continue the monitoring after March 2018 (i.e., beyond the period of funding from OrganiCity) — having 12 months of data or more would be valuable to us and to our partners.
FOMBL/Greening Our Street:
Can the monitoring help identify ‘green tunnels’ through the city? This would be really valuable information for shaping future biodiversity initiatives.
City of Edinburgh Council:
Because it is time-consuming and expensive to collect biodiversity data, much of the information about sites across the city is out of date. It would be very useful if IoT technology could be used to get much more timely biodiversity data. Amongst other things, this would give evidence to support continued protection of those greenspaces.
The Sonic Art Exhibition
We revisited plans for the end-of-project exhibition and event and considered whether to adapt or expand it. This event is intended to be both a response to the audio assets collected by project and simultaneously a way of engaging with the public. Martin Parker explained his original conception, where six speakers would each be controlled by a location-aware app on a phone, determining what, how and when sound comes out of the speaker. In addition, the speakers would be movable, and members of the audience could arrange and re-organise the soundscape within the physical exhibition space.
Ideas that we discussed included:
How can we build a biodiversity storytelling aspect to the sounds? Should we, for example, include information about bats as an accompaniment to the audio?
How will we represent ultrasonic sounds to the public?
Can we capture different times of day on speakers, so that people can hear sounds associated with the night, the morning etc.
Should we associate sounds from different parts of the Meadows with different parts of the room?
We are still working out the best processes and activities for our two data literacy workshops and the final sonic art exhibition, so watch out for further blog posts!