Towards soundscape management of protected natural areas using the ISO 12913: A field study

Human perception of soundscapes in protected natural areas like national parks is crucial for their protection. At popular scenic spots, visitors themselves often contribute to noise pollution. Decibel-based systems (such as LAeq or Lden) do not fully explain human reactions to this phenomenon, necessitating a more holistic approach to allow for an effective management strategy. A mixed-methods soundscape approach based on the ISO 12913 series, developed mostly in urban soundscape studies, was tested in four protected natural ex-urban areas in the Dolomites (Italy) and Cairngorms (United Kingdom). During five soundwalks (7-12 km long), conducted by adopting the Method A of ISO/TS 12913-2, a total of 443 questionnaire responses were gathered across 28 evaluation points, alongside corresponding binaural measurements. A range of acoustic environments as quiet as LAeq = 31 dBA and as loud as LAeq = 76 dBA were observed, eliciting perceptions ranging from very calm to chaotic. A Linear Mixed-Effects Model was computed to analyse the impact of sound source dominance, psychoacoustic and environmental acoustic indices on perception. Presence of human sounds proved to be a major factor driving the perception of chaotic soundscapes.