Paris has reduced urban noise levels by about three decibels over the past decade, according to reporting from The Conversation. The improvement is attributed to campaigns and measures aimed at cutting noise pollution. Despite this progress, the sources note that city conditions continue to affect wildlife. In particular, birds still change their singing behavior in response to ongoing traffic noise. Even with a quieter soundscape than ten years ago, the residual noise from vehicles remains loud enough to push many birds to sing at a higher pitch than they would in more natural, quieter environments.
Taken together, the articles describe a partial success: noise pollution policies lower overall noise, but they do not fully restore the acoustic conditions birds need to sing at their natural frequencies. The difference between the reduction in background noise and the continued impact on bird communication highlights that noise regulation can improve urban conditions while leaving some ecological effects still present. The sources focus on how traffic noise influences bird calls and the persistence of that effect.
