The sound of birds singing can make people feel calmer and more comfortable. Yet certain bird calls appear to be especially enjoyable to human listeners, and scientists are starting to identify the reasons behind that response. Throughout much of human evolution, the everyday sounds of birds may have served as a comforting sign that the area nearby was safe and relatively free from threats. New research suggests that particular acoustic traits may explain why some bird songs appeal to people

It is huge. It is beloved by aviation fans. It is unmistakably past its peak. And it has returned from the brink more times than many expected. Yet as Australia’s national carrier Qantas prepares to phase out its fleet of Airbus A380 superjumbos, known for their spacious full-length double decks, a larger question remains: has the world’s biggest passenger aircraft finally reached the end of its era? Qantas announced in August that it intends to begin retiring its 10 A380s in 2028, four years