20th Field Trip to Alice Holt Forest

22 May 2025 by Peter Batchelor

Self-portrait of Peter Batchelor, Dendrophone and Paula the Streamer.

On 17 May I made my first trip to Alice Holt since February. Luigi has kindly been overseeing and undertaking battery changes for all our interventions in the meantime, but there were some modifications I wanted to make to the installation and setup ready for the summer.

This weekend’s visit was to:

install a battery monitor based on a circuit and code shared by Luigi; I now receive an hourly update of the battery condition by email while the installation is running.
update installation — this involved relatively minimal intervention, just to increase levels of what was already there and ensure all three layers are clearly audible and distinguishable. As per publicity, the parameters now represented are:
- RH — mapped to dryness/wetness of sounds;
- PAR (Photosynthetically Active Radiation) — mapped to pitch (transposition) of a drone;
- Photosynthetic Activity (derived from PAR+Air Temperature) — mapped to amplitude modulation of drone to produce a ‘judder’, implying photosynthetic ‘busy-ness’;
- CO2 — mapped to regularity of synthesised breathing.

While in the forest I addressed some minor ‘wear and tear’ and ‘unsolicited public intervention’ issues:

cleaned solar panels for both installation and streamer, which had accumulated grime, algae and detritus (I estimate efficiency was being compromised by at least 5% from these, given the cells occluded).
optimised signag (one had been uprooted and moved, and both needed cleaning); I attached my signage to a tree directly adjacent to my installation.
notified the team of a missing QR code on Luigi’s signage (a replacement has been ordered).
straightened some misaligned speaker boxes (with a stick, in the absence of a ladder!)

Beyond this, the speakers are looking a little weathered, but so far all 16 remain connected and functional. I’m a little concerned about one of the cable lengths between trees, which has dropped (I suspect the steel cable has snapped), so that it’s within reach from the ground; this may invite tampering, so I shall need to keep an eye on it.

The installation has now been running 11am-5pm (10-4 in winter) without interruption since September, bar a few occasions over the winter when the battery expired due to low solar charge (limited daylight, low solar angle and poor weather). I’m pleased that this seems to demonstrate the robustness of the chosen components and of the system overall. I’m also satisfied that the modified levels ensure that the installation’s more audible while remaining acoustically transparent and unobtrusive, and I think it sits reasonably comfortably within the existing soundscape.