A quacking car horn designed to alert people to danger while reducing the cacophony of noise on city streets has been developed by sound experts.
The device, sounding a little like a synthesised duck, was developed to get attention in a less stressful way than the traditional angry honk.
Scientists returned to the early days of motoring and re-modelled the classic Klaxon "ah-oo-gah" car horn introduced in 1908.
Different sound variations were tested on 100 volunteers before deciding on the pedestrian-friendly "quack".
Lead researcher Professor Myung Jin Bae, from Soongsil University in Seoul, South Korea, said: "In our study we used the existing historic Klaxon sound source, but made some modification concerning its volume and rhythm with duration time by adding a power controller.