The Project

Edinburgh Zoo raised serious concerns about construction noise impacting their premises due to a nearby housing development. The initial noise and vibration Environmental Impact Assessment (EIA) overlooked animal sensitivities, relying solely on the human-focused BS 5228 standard. Recognizing this gap, Xi Engineering Consultants helped to ensure the welfare of the animals of Edinburgh Zoo and especially the highly sensitive Giant Pandas. These pandas, vital for the China-Scotland relationship and tourism, faced distress from loud construction noise. This highlighted the need for a specialized assessment beyond human auditory capabilities, emphasizing the urgency to protect the pandas’ well-being amidst construction disruptions.

Acoustic Investigation

Xi Engineering Consultants conducted an in-depth review of literature focusing on the impact of noise on the well-being of Giant Pandas to complete the Environmental Impact Assessment (EIA) specific to these species at Edinburgh Zoo. Studies have highlighted alarming effects of prolonged exposure to loud noise on Giant Pandas, evident in behavioural changes and the production of stress hormones (Owen et al., 2004). With an impressive hearing range spanning from 0.1 kHz to 70 kHz, far surpassing human auditory capabilities, Giant Pandas can be disturbed by noises that remain unheard by the human ear. This striking difference emphasizes the failing of relying solely on British Standard evaluations, designed for human receptors, to assess the impact of noise on species as sensitive as the Giant Panda.

Comparison of Human & Panda Noise Threshold | Edinburgh Zoo Giant Pandas | Xi Engineering Consultants

Panda hearing curve [Owen at al. 2016] compared against the human hearing curve. Note. Logarithmic frequency axis.

Noise Impact Assessment Specialised for Animals

Xi Engineering Consultants conducted a comprehensive noise and vibration Environmental Impact Assessment (EIA) at Edinburgh Zoo, utilizing the industry-standard BS 5228 alongside specialized equipment. In addition to standard measurement tools, an ultra-sonic noise level meter captured frequencies between 20 kHz and 100 kHz. This data was calibrated against the Type-1 sound level meter, enabling a thorough baseline assessment for rating the noise impact from the neighbouring construction site.

Acoustic Measurement | Edinburgh Zoo Giant Pandas | Xi Engineering Consultants

The subsequent phase involved predicting noise levels from the construction site. While commercially available software, along with BS 5228-rated noise levels, was initially used to anticipate noise impact within the human hearing range, the addition of the ultra-sonic noise meter at the construction site revealed previously undetected high acoustic energy in the ultra-sonic spectrum.

Data analysis & results of the Noise Impact Assessment

Analysis highlighted a notable increase in noise within the Panda hearing range due to this unseen acoustic energy, primarily from tonal noise emitted by rotating equipment harmonics. Tonal noise, considered highly disruptive and irritating, raised concerns regarding potential distress to the Giant Pandas. Edinburgh Zoo, once aware of this impact, faced the critical responsibility of acting in the animals’ best interests. Failure to do so put the Zoo’s ability to keep the Giant Panda’s at risk, underlining the significance of addressing this noise disturbance for the well-being of the animals.

Liaising with all relevant parties & setting legal noise limits

After assessing the situation and predicting construction noise levels, Xi produced an Acoustic and Vibration Method Statement. This document set noise limits for the construction site and mandated a 2m high acoustic barrier along the Zoo’s perimeter during development phases. Acting as a technical consultant, Xi Engineering Consultants ensured thorough noise and vibration monitoring, assisting in parallel with animal distress signs. Xi’s acoustic findings prompted concern for Giant Pandas’ well-being. This led to the Scottish Government and the Zoo jointly planning a new enclosure tailored to Panda needs.

Designing the Giant Panda enclosure

Xi played a crucial role in optimizing the acoustic aspects of the Giant Panda’s enclosure by using multiphysics simulation. Our involvement ensured that every design feature considered the impact of sound on the Giant Pandas. Collaborating closely with various expert consultancies through extensive design team meetings and precise part specifications, Xi Engineering Consultants contributed to the development of the specialized panda enclosure at Edinburgh Zoo.

Following thorough planning and dedicated efforts, both pandas resided comfortably in their tailor-made habitats within the soundproof enclosure. This significant achievement marked a crucial moment as the exhibit opened its doors to the general public, offering a space where visitors could witness the Giant Pandas in an environment specifically crafted to meet their unique needs.

Panda Enclosure | Acoustic Simulation | Edinburgh Zoo | Xi Engineering Consultants | Edinburgh Zoo Giant Pandas

“Xi Engineering Consultants provided excellent advice and a very professional service.”

Barbara Smith, Chief Executive Officer, The Royal Zoological Society of Scotland.