One quarter of all terrestrial native bird species have become extinct since human arrival in New Zealand,  leading to a pervasive silence in many natural environments due to the decrease in native bird song. Passive  acoustic techniques are a potential tool for environmental monitoring, especially for testing whether the control  of mammals can reverse the ‘silent forest’ effect. Here we compare soundscapes from two nearby sites within the  Waitakere Ranges Regional Park, New Zealand, that have contrasting predator control levels: one with high-level  pest mammal control, and the other with low-level pest control. Measurements of twelve acoustic indices  extracted from two seasons of passive acoustic recordings are split into 20 acoustic regions to identify which  regions best discriminate between the two management regimes. We define the acoustic regions as units of  analysis bounded by a specific time period and frequency range chosen to capture the main groups of biologically  relevant acoustic events within a soundscape. Analysis of variance and pairwise comparisons indicated the  acoustic region bounded from 9 pm to 11:59 pm and a range of 0.988–3.609 kHz in autumn presented the  greatest differences between sites. The sounds responsible for these acoustic differences were generated by  invasive mammals in the site with no pest control. Results also supports spring season as the most important for  bird monitoring in New Zealand. Acoustic indices analysis did not detect a reversal of the “silence forest” effect in  the site with high-level predator control.