The sound produced by human-made machinery (technophony) is known to exert negative effects on animal
communication and well-being. Mining is an important economic activity in Brazil, which is often conducted
close to forested areas and produces a diffuse noise. In this study, the impact of such noise on biophony (biological
sounds)was investigated by characterizing and comparing the soundscapes of two different sites (close versus distant
froman open-castmine) in the same Atlantic forest fragment,matched for habitat type, in Southeast Brazil. Six
automated recorderswere installed at each site andwere programmed to record continuously during seven consecutive
days every two months between October 2012 and August 2013. Technophony and biophony valueswere
derived from power spectra and the Acoustic Complexity Index (ACI). Mann–Whitney U tests demonstrated that
the biophony exhibited a switch in daily dynamics, resulting in a statistically higher biophony during the day at the
site close to the mine and a higher biophony during the night at the site far from the mine. Potential species richness
was found to be higher at the site thatwas distant fromthe mine. The species composition and spectral characteristics
of the calls were also found to differ between the two sites. These results provide the first investigation
of potential disturbances caused by mining noise on biophony, demonstrating that it can cause alterations in the
temporal dynamics and daily patterns of animal sounds, which are symptoms of altered behaviors or variations
in community-species composition. These findings suggest remarkable insights that should be taken into consideration
in the regulating of the use of natural areas for mining.